# DevTools Surf

> 543+ free online developer tools including the REST Handler (simple REST client with collections, env vars, history, cURL ↔ Collection JSON converter). Every tool runs in the browser — no signup, no uploads, no data sent to servers. Fast, privacy-first, client-side.

## About

- Name: DevTools Surf
- URL: https://devtools.surf
- Tools: 543
- Categories: 28
- Privacy: client-side; no user input is transmitted to third parties
- License: MIT for open tools; proprietary UI

## Flagship

- [REST Handler](https://devtools.surf/tools/rest-handler): Simple REST client — collections (nested), environment variables, request history, and format converter between cURL, Collection JSON v2.1, and the REST Handler YAML format.

## Categories

- [JSON](https://devtools.surf/tools/category/json): 18 tools
- [HTML](https://devtools.surf/tools/category/html): 6 tools
- [XML](https://devtools.surf/tools/category/xml): 10 tools
- [YAML](https://devtools.surf/tools/category/yaml): 6 tools
- [CSS](https://devtools.surf/tools/category/css): 49 tools
- [JavaScript](https://devtools.surf/tools/category/js): 2 tools
- [Converters](https://devtools.surf/tools/category/converter): 42 tools
- [Images](https://devtools.surf/tools/category/images): 25 tools
- [Text / String](https://devtools.surf/tools/category/text): 60 tools
- [Encoding](https://devtools.surf/tools/category/encoding): 12 tools
- [Generators](https://devtools.surf/tools/category/generators): 41 tools
- [Color](https://devtools.surf/tools/category/color): 23 tools
- [Networking](https://devtools.surf/tools/category/networking): 23 tools
- [PDF](https://devtools.surf/tools/category/pdf): 6 tools
- [API / Config](https://devtools.surf/tools/category/api): 7 tools
- [Date / Time](https://devtools.surf/tools/category/datetime): 14 tools
- [Security / Crypto](https://devtools.surf/tools/category/security): 18 tools
- [Web / Frontend](https://devtools.surf/tools/category/web): 23 tools
- [Data / SQL](https://devtools.surf/tools/category/data): 10 tools
- [AI / Modern Dev](https://devtools.surf/tools/category/ai): 5 tools
- [Fun / Niche](https://devtools.surf/tools/category/fun): 30 tools
- [Developer Utilities](https://devtools.surf/tools/category/devutils): 18 tools
- [Game Dev](https://devtools.surf/tools/category/gaming): 16 tools
- [Animation / CSS](https://devtools.surf/tools/category/animation): 10 tools
- [Calculators](https://devtools.surf/tools/category/calculators): 15 tools
- [Audio](https://devtools.surf/tools/category/audio): 4 tools
- [Cheatsheets](https://devtools.surf/tools/category/cheatsheet): 25 tools
- [Info / Guides](https://devtools.surf/tools/category/info): 25 tools

## Tools

### JSON

- [JSON Formatter](https://devtools.surf/tools/json-formatter): Format and prettify JSON with syntax highlighting
- [JSON Validator](https://devtools.surf/tools/json-validator): Validate JSON syntax and structure
- [JSON Viewer](https://devtools.surf/tools/json-viewer): Explore JSON data in a tree view
- [JSON Stringify](https://devtools.surf/tools/json-stringify): Convert JSON to escaped string representation
- [JSON Patch](https://devtools.surf/tools/json-patch): Generate or apply RFC 6902 JSON Patch operations
- [JSON Diff](https://devtools.surf/tools/json-diff): Compare two JSON documents and show structural differences
- [JSONPath Tester](https://devtools.surf/tools/jsonpath-tester): Test JSONPath expressions against a JSON document
- [JSON Sort Keys](https://devtools.surf/tools/json-sort-keys): Recursively sort all keys in a JSON document alphabetically
- [JSON Flatten / Unflatten](https://devtools.surf/tools/json-flatten): Flatten nested JSON to dot-notation or unflatten back
- [JSON Minifier](https://devtools.surf/tools/json-minifier): Minify JSON with size statistics
- [JSON Merge / Deep Merge](https://devtools.surf/tools/json-merge): Deep merge two JSON objects together
- [JSON ↔ JSON5](https://devtools.surf/tools/json5-converter): Convert between strict JSON and relaxed JSON5 format
- [NDJSON / JSONL Viewer](https://devtools.surf/tools/ndjson-viewer): Parse and display newline-delimited JSON line by line
- [JSON Path Finder](https://devtools.surf/tools/json-path-finder): Enter JSON and a value to get every JSONPath that matches
- [Smart JSON Diff](https://devtools.surf/tools/diff-two-json): Structural diff between two JSON docs with summary stats
- [JSON Escape String](https://devtools.surf/tools/json-escape-string): Escape any text as a JSON-safe string with \n \t \uXXXX handling
- [JSON Unescape String](https://devtools.surf/tools/json-unescape-string): Reverse JSON escape sequences back to raw text
- [JMESPath Tester](https://devtools.surf/tools/jmespath-tester): Query JSON with JMESPath expressions + live result + examples

### HTML

- [HTML Formatter](https://devtools.surf/tools/html-formatter): Format and indent HTML code
- [HTML Pretty Print](https://devtools.surf/tools/html-pretty-print): Pretty print HTML with color-coded output
- [HTML Validator](https://devtools.surf/tools/html-validator): Validate HTML markup and structure
- [HTML Viewer](https://devtools.surf/tools/html-viewer): Preview and inspect HTML in real-time
- [HTML Minify](https://devtools.surf/tools/html-minify): Minify HTML by removing whitespace and comments
- [HTML → Plain Text](https://devtools.surf/tools/html-to-text): Strip tags, decode entities, preserve paragraph breaks

### XML

- [XML Formatter](https://devtools.surf/tools/xml-formatter): Format and prettify XML documents
- [XML Minify](https://devtools.surf/tools/xml-minify): Minify XML by removing whitespace
- [XML Viewer](https://devtools.surf/tools/xml-viewer): View XML in a structured tree format
- [XML Pretty Print](https://devtools.surf/tools/xml-pretty-print): Pretty print XML with syntax highlighting
- [XML Validator](https://devtools.surf/tools/xml-validator): Validate XML syntax and well-formedness
- [XML Editor](https://devtools.surf/tools/xml-editor): Edit XML with real-time validation and highlighting
- [XML Parser](https://devtools.surf/tools/xml-parser): Parse XML and extract structured data
- [WSDL Formatter](https://devtools.surf/tools/wsdl-formatter): Format WSDL (Web Services Description Language) files
- [SOAP Formatter](https://devtools.surf/tools/soap-formatter): Format SOAP XML messages
- [XML Schema (XSD) Validator](https://devtools.surf/tools/xml-schema-validator): Validate XML against basic XSD schema rules

### YAML

- [YAML Validator](https://devtools.surf/tools/yaml-validator): Validate YAML syntax and structure
- [YAML Viewer](https://devtools.surf/tools/yaml-viewer): View YAML in a structured tree format
- [YAML Formatter](https://devtools.surf/tools/yaml-formatter): Format and prettify YAML documents
- [YAML Parser](https://devtools.surf/tools/yaml-parser): Parse YAML and extract structured data
- [YAML Multi-Doc Splitter](https://devtools.surf/tools/yaml-multi-doc-splitter): Split a multi-document YAML file into separate documents
- [YAML Anchor Expander](https://devtools.surf/tools/yaml-anchor-expander): Expand YAML anchors and aliases into plain YAML

### CSS

- [Minify CSS](https://devtools.surf/tools/css-minify): Minify CSS by removing whitespace and comments
- [CSS Beautifier](https://devtools.surf/tools/css-beautifier): Beautify and format CSS code
- [CSS Formatter](https://devtools.surf/tools/css-formatter): Format CSS with proper indentation
- [CSS Pretty Print](https://devtools.surf/tools/css-pretty-print): Pretty print CSS with color coding
- [CSS to LESS](https://devtools.surf/tools/css-to-less): Convert CSS to LESS preprocessor syntax
- [CSS to SCSS](https://devtools.surf/tools/css-to-scss): Convert CSS to SCSS preprocessor syntax
- [CSS to SASS](https://devtools.surf/tools/css-to-sass): Convert CSS to SASS syntax
- [CSS to Stylus](https://devtools.surf/tools/css-to-stylus): Convert CSS to Stylus syntax
- [Stylus to CSS](https://devtools.surf/tools/stylus-to-css): Convert Stylus to standard CSS
- [Stylus to LESS](https://devtools.surf/tools/stylus-to-less): Convert Stylus to LESS syntax
- [Stylus to SCSS](https://devtools.surf/tools/stylus-to-scss): Convert Stylus to SCSS syntax
- [Stylus to SASS](https://devtools.surf/tools/stylus-to-sass): Convert Stylus to SASS syntax
- [LESS to CSS](https://devtools.surf/tools/less-to-css): Convert LESS to standard CSS
- [LESS to SCSS](https://devtools.surf/tools/less-to-scss): Convert LESS to SCSS syntax
- [LESS to SASS](https://devtools.surf/tools/less-to-sass): Convert LESS to SASS syntax
- [LESS to Stylus](https://devtools.surf/tools/less-to-stylus): Convert LESS to Stylus syntax
- [SCSS to CSS](https://devtools.surf/tools/scss-to-css): Convert SCSS to standard CSS
- [SCSS to LESS](https://devtools.surf/tools/scss-to-less): Convert SCSS to LESS syntax
- [SCSS to SASS](https://devtools.surf/tools/scss-to-sass): Convert SCSS to SASS syntax
- [SCSS to Stylus](https://devtools.surf/tools/scss-to-stylus): Convert SCSS to Stylus syntax
- [SASS to CSS](https://devtools.surf/tools/sass-to-css): Convert SASS to standard CSS
- [SASS to LESS](https://devtools.surf/tools/sass-to-less): Convert SASS to LESS syntax
- [SASS to SCSS](https://devtools.surf/tools/sass-to-scss): Convert SASS to SCSS syntax
- [SASS to Stylus](https://devtools.surf/tools/sass-to-stylus): Convert SASS to Stylus syntax
- [CSS Grid Generator](https://devtools.surf/tools/css-grid-generator): Generate grid-template CSS with custom cols, rows, and gap
- [CSS Border Builder](https://devtools.surf/tools/css-border-builder): Build border CSS — width, style, color, radius, per-side control
- [CSS Text Shadow](https://devtools.surf/tools/css-text-shadow): Build text-shadow with x, y, blur, color — includes neon/retro presets
- [CSS Filter Builder](https://devtools.surf/tools/css-filter-builder): Chain blur, brightness, contrast, hue-rotate, saturate, sepia
- [CSS Transform Builder](https://devtools.surf/tools/css-transform-builder): Build transform() — translate, rotate, scale, skew, 3D rotations
- [CSS Glassmorphism](https://devtools.surf/tools/css-glassmorphism): Generate frosted-glass UI — backdrop-filter blur + transparent bg
- [CSS Neumorphism](https://devtools.surf/tools/css-neumorphism): Soft-UI box-shadow combinations — raised, inset, and flat modes
- [CSS Button Styles](https://devtools.surf/tools/css-button-styles): Modern button CSS — lift hover, shadow, colors, radius, padding
- [CSS Tooltip Builder](https://devtools.surf/tools/css-tooltip-builder): Pure-CSS tooltip from data-attr — top/bottom/left/right positions
- [CSS Card Builder](https://devtools.surf/tools/css-card-builder): Elevated card with hover-lift + shadow — fully customizable
- [CSS Form Styler](https://devtools.surf/tools/css-form-styler): Style inputs, textareas, selects — focus ring, accent color, radius
- [CSS Accordion Builder](https://devtools.surf/tools/css-accordion-builder): Zero-JS accordion using <details>/<summary> + CSS animation
- [CSS Tabs Builder](https://devtools.surf/tools/css-tabs-builder): Accessible tab bar with aria-selected styling + bottom accent
- [CSS Modal Builder](https://devtools.surf/tools/css-modal-builder): Native <dialog> modal with backdrop blur + entrance animation
- [CSS Checkbox Styler](https://devtools.surf/tools/css-checkbox-styler): Custom checkbox with CSS-only checkmark — accent & size control
- [CSS Switch / Toggle](https://devtools.surf/tools/css-switch-toggle): iOS-style toggle switch — slider moves on :checked
- [CSS Progress Bar](https://devtools.surf/tools/css-progress-bar): Gradient progress bar with animated shimmer — accessible
- [CSS Ribbon Builder](https://devtools.surf/tools/css-ribbon-builder): Corner ribbon label using clip-path — content via data-ribbon attr
- [CSS Avatar Builder](https://devtools.surf/tools/css-avatar-builder): Circular/square avatar with initials, ring, image fallback
- [CSS Flip Card](https://devtools.surf/tools/css-flip-card): 3D hover-flip card using perspective + backface-visibility
- [CSS Dropdown Builder](https://devtools.surf/tools/css-dropdown-builder): Hover + focus-within dropdown — zero JS, animated
- [CSS Breadcrumb Builder](https://devtools.surf/tools/css-breadcrumb-builder): Navigation breadcrumb with custom separator — /, >, arrow
- [CSS Arrow Generator](https://devtools.surf/tools/css-arrow-generator): Pure-CSS arrow (up/down/left/right) using rotated borders
- [CSS Triangle Generator](https://devtools.surf/tools/css-triangle-generator): Zero-element triangle using transparent borders — any direction
- [CSS Divider Builder](https://devtools.surf/tools/css-divider-builder): Horizontal rule — solid/dashed/dotted or labeled (OR, AND, etc)

### JavaScript

- [JS Beautifier](https://devtools.surf/tools/js-beautifier): Beautify and format JavaScript code
- [Javascript Pretty Print](https://devtools.surf/tools/js-pretty-print): Pretty print JavaScript with syntax highlighting

### Converters

- [JSON to XML](https://devtools.surf/tools/json-to-xml): Convert JSON data to XML format
- [JSON to CSV](https://devtools.surf/tools/json-to-csv): Convert JSON array to CSV format
- [JSON to YAML](https://devtools.surf/tools/json-to-yaml): Convert JSON to YAML format
- [JSON to TSV](https://devtools.surf/tools/json-to-tsv): Convert JSON array to Tab-Separated Values
- [JSON to String](https://devtools.surf/tools/json-to-string): Convert JSON to escaped string format
- [XML to JSON](https://devtools.surf/tools/xml-to-json): Convert XML to JSON format
- [XML to CSV](https://devtools.surf/tools/xml-to-csv): Convert XML data to CSV format
- [XML to String](https://devtools.surf/tools/xml-to-string): Convert XML to escaped string
- [XML to YAML](https://devtools.surf/tools/xml-to-yaml): Convert XML to YAML format
- [RSS to JSON](https://devtools.surf/tools/rss-to-json): Convert RSS/Atom feed to JSON format
- [YAML to JSON](https://devtools.surf/tools/yaml-to-json): Convert YAML to JSON format
- [YAML to XML](https://devtools.surf/tools/yaml-to-xml): Convert YAML to XML format
- [YAML to CSV](https://devtools.surf/tools/yaml-to-csv): Convert YAML array to CSV format
- [CSV to JSON](https://devtools.surf/tools/csv-to-json): Convert CSV data to JSON format
- [CSV to XML](https://devtools.surf/tools/csv-to-xml): Convert CSV data to XML format
- [CSV to YAML](https://devtools.surf/tools/csv-to-yaml): Convert CSV data to YAML format
- [CSV to HTML](https://devtools.surf/tools/csv-to-html): Convert CSV data to HTML table
- [String to JSON](https://devtools.surf/tools/string-to-json): Parse stringified JSON back to formatted JSON
- [String to XML](https://devtools.surf/tools/string-to-xml): Parse stringified XML back to formatted XML
- [BSON ↔ JSON](https://devtools.surf/tools/bson-to-json): Convert between BSON hex and JSON
- [INI ↔ JSON](https://devtools.surf/tools/ini-to-json): Convert between INI config files and JSON
- [HCL (Terraform) ↔ JSON](https://devtools.surf/tools/hcl-to-json): Convert between HCL/Terraform config and JSON
- [EDN ↔ JSON](https://devtools.surf/tools/edn-to-json): Convert between Clojure EDN and JSON formats
- [JSON → Go Struct](https://devtools.surf/tools/json-to-go-struct): Convert JSON to Go struct definitions with json tags
- [YAML → .env](https://devtools.surf/tools/yaml-to-env): Flatten a YAML file to KEY=value lines
- [.env → YAML](https://devtools.surf/tools/env-to-yaml): Group dotted KEY_NAME pairs back into a YAML tree
- [JSON → Zod Schema](https://devtools.surf/tools/json-to-zod): Derive a runtime-validatable Zod schema from a JSON sample
- [JSON → .env](https://devtools.surf/tools/json-to-env): Flatten a JSON object into UPPER_SNAKE KEY=value lines
- [.env → JSON](https://devtools.surf/tools/env-to-json): Parse KEY=value lines (with quotes + comments) into a JSON object
- [JSON → TypeScript Types](https://devtools.surf/tools/json-to-typescript-types): Infer TypeScript interfaces from JSON with deep nesting + optionals
- [JSON → Python Dict](https://devtools.surf/tools/json-to-python-dict): Convert JSON to a valid Python dict literal (True/False/None)
- [JSON → PHP Array](https://devtools.surf/tools/json-to-php-array): Convert JSON to a PHP 5.4+ short-syntax associative array
- [JSON → Ruby Hash](https://devtools.surf/tools/json-to-ruby-hash): Convert JSON to a Ruby hash with symbol or string keys
- [JSON → Java Class](https://devtools.surf/tools/json-to-java-class): Generate a POJO Java class with getters/setters from a JSON sample
- [JSON → Swift Struct](https://devtools.surf/tools/json-to-swift-struct): Generate a Codable Swift struct from a JSON sample
- [JSON → Kotlin Class](https://devtools.surf/tools/json-to-kotlin-class): Generate a Kotlin data class from a JSON sample
- [JSON → Rust Struct](https://devtools.surf/tools/json-to-rust-struct): Generate a serde-compatible Rust struct from a JSON sample
- [JSON → C# Class](https://devtools.surf/tools/json-to-csharp-class): Generate a C# class with properties + nullables from JSON
- [JSON → Dart Class](https://devtools.surf/tools/json-to-dart-class): Generate a Dart class with fromJson/toJson from a JSON sample
- [JSON Schema → TypeScript](https://devtools.surf/tools/json-schema-to-typescript): Convert a JSON Schema draft-07 document into TypeScript types
- [JSON → MongoDB Query](https://devtools.surf/tools/json-to-mongodb-query): Convert flat key-value JSON into a MongoDB find() query object
- [JSON → Query String](https://devtools.surf/tools/json-to-query-string): Serialize a flat JSON object into a URL query string

### Images

- [Sample Images](https://devtools.surf/tools/sample-images): Download standard-size placeholder images or generate a custom size
- [Image Converter](https://devtools.surf/tools/image-converter): Convert images between PNG, JPEG, WebP and more
- [Bulk Image Converter](https://devtools.surf/tools/bulk-image-converter): Convert multiple images at once to a chosen format
- [Image Editor](https://devtools.surf/tools/image-editor): Crop, annotate, draw, and add text to images
- [Aspect Ratio Calculator](https://devtools.surf/tools/aspect-ratio-calculator): Calculate aspect ratios and resize dimensions proportionally
- [SVG Optimizer](https://devtools.surf/tools/svg-optimizer): Minify and clean SVG markup by removing metadata and comments
- [Favicon Generator](https://devtools.surf/tools/favicon-generator): Generate a favicon pack from a single image or emoji
- [Lorem Picsum Picker](https://devtools.surf/tools/picsum-picker): Browse and download curated placeholder images
- [Avatar / Initials Generator](https://devtools.surf/tools/avatar-generator): Create initials-based SVG avatars from a name
- [Image Metadata Viewer](https://devtools.surf/tools/image-metadata-viewer): Show EXIF / IPTC / XMP metadata from JPEG, PNG, HEIF
- [Base64 ↔ Image](https://devtools.surf/tools/base64-image): Encode an image to a data URL, or decode a data URL back to an image
- [Image Palette Extractor](https://devtools.surf/tools/image-palette-extractor): Extract the dominant colors from an image
- [Image Resizer (Batch)](https://devtools.surf/tools/image-resizer-batch): Resize and crop multiple images in the browser
- [WebP ↔ AVIF Converter](https://devtools.surf/tools/webp-avif-converter): Convert images between WebP, AVIF, PNG, and JPEG in-browser
- [Video Thumbnail Extractor](https://devtools.surf/tools/video-thumbnail): Scrub a video and export a frame as a PNG or JPEG
- [Image Compressor](https://devtools.surf/tools/image-compressor): Client-side JPEG compression with quality + scale sliders — no upload
- [Image Grayscale](https://devtools.surf/tools/image-grayscale): Desaturate any image — 0–100% grayscale, preview + download
- [Image Rotator](https://devtools.surf/tools/image-rotator): Rotate an image by any angle — canvas re-fits to new bounds
- [Image Cropper](https://devtools.surf/tools/image-cropper): Crop an image from left/top/right/bottom with % sliders
- [Image Color Inverter](https://devtools.surf/tools/image-invert): Invert every pixel's RGB — negative / X-ray effect
- [Image Watermark](https://devtools.surf/tools/image-watermark): Tile a text watermark across any image — opacity + angle control
- [ASCII Art Generator](https://devtools.surf/tools/ascii-art-generator): Convert photos to ASCII art — dense / simple / block ramps
- [Image Blur](https://devtools.surf/tools/image-blur): Apply canvas blur (0–40px) — great for hero backgrounds
- [Image Brightness / Contrast](https://devtools.surf/tools/image-brightness-contrast): Adjust brightness, contrast, and saturation in one pass
- [Image Flip / Mirror](https://devtools.surf/tools/image-flip-mirror): Horizontal or vertical mirror — or both — of any image

### Text / String

- [URL Encoder](https://devtools.surf/tools/url-encoder): Encode strings for safe URL usage
- [URL Decoder](https://devtools.surf/tools/url-decoder): Decode percent-encoded URL strings
- [HTML Entity Encode](https://devtools.surf/tools/html-entity-encode): Convert characters to HTML entities
- [HTML Entity Decode](https://devtools.surf/tools/html-entity-decode): Convert HTML entities back to characters
- [JWT Decoder](https://devtools.surf/tools/jwt-decoder): Decode and inspect JWT token header and payload
- [Lorem Ipsum Generator](https://devtools.surf/tools/lorem-ipsum-generator): Generate placeholder text in words, sentences, or paragraphs
- [Word Counter](https://devtools.surf/tools/word-counter): Count words, characters, sentences, paragraphs, and reading time
- [Text Diff](https://devtools.surf/tools/text-diff): Compare two text blocks and highlight differences
- [Case Converter](https://devtools.surf/tools/case-converter): Convert between camelCase, snake_case, PascalCase, kebab-case, and more
- [Line Sorter](https://devtools.surf/tools/line-sorter): Sort lines alphabetically, numerically, reverse, shuffle, or dedupe
- [Regex Tester](https://devtools.surf/tools/regex-tester): Test regex patterns with match highlighting and group extraction
- [String Escape / Unescape](https://devtools.surf/tools/string-escape): Escape and unescape strings for JS, JSON, HTML, or SQL
- [Markdown Preview](https://devtools.surf/tools/markdown-preview): Live preview rendered Markdown with syntax highlighting
- [.env Validator](https://devtools.surf/tools/env-validator): Validate .env files and flag missing values or duplicate keys
- [Byte Counter](https://devtools.surf/tools/byte-counter): Show byte size of text in UTF-8, UTF-16, and ASCII
- [TOML Formatter](https://devtools.surf/tools/toml-formatter): Format and validate TOML configuration files
- [Markdown Table Editor](https://devtools.surf/tools/markdown-table-editor): Edit Markdown tables with a visual grid — add rows and align cells
- [JWT to cURL](https://devtools.surf/tools/jwt-to-curl): Generate a curl command that uses a JWT as the Authorization header
- [Diff Viewer (Side-by-Side)](https://devtools.surf/tools/diff-viewer): View unified or side-by-side diffs with syntax highlighting
- [Environment Variable Diff](https://devtools.surf/tools/env-diff): Compare two .env files and show added, removed, and changed variables
- [Unicode Normalizer](https://devtools.surf/tools/unicode-normalizer): Normalize Unicode text between NFC, NFD, NFKC, and NFKD forms
- [Markdown Resume Builder](https://devtools.surf/tools/markdown-resume-builder): Write a resume in Markdown and export to styled HTML or PDF
- [Regex Cheatsheet](https://devtools.surf/tools/regex-cheatsheet): Searchable reference of regex syntax with live examples
- [Unicode Escape](https://devtools.surf/tools/unicode-escape): Escape non-ASCII chars as \uXXXX or decode them back
- [Pronouncing Counter](https://devtools.surf/tools/pronouncing-counter): Count syllables per word (useful for copy + slugs)
- [Readability Scorer](https://devtools.surf/tools/readability-scorer): Flesch + grade-level estimate for any prose block
- [Word Frequency Counter](https://devtools.surf/tools/word-frequency): Rank words by frequency, stop-words filtered
- [Clipboard Cleaner](https://devtools.surf/tools/clipboard-cleaner): Strip smart quotes, zero-widths, non-breaking spaces
- [Markdown TOC](https://devtools.surf/tools/markdown-toc): Generate a table of contents from markdown headings
- [Whitespace Visualizer](https://devtools.surf/tools/whitespace-visualizer): Render spaces, tabs, newlines, zero-widths as glyphs
- [Line Deduper](https://devtools.surf/tools/line-deduper): Remove duplicate lines, preserve order or sort
- [Hard Wrap](https://devtools.surf/tools/text-wrap): Re-wrap prose to a fixed column width
- [IETF Language Tag Validator](https://devtools.surf/tools/ietf-tag-validator): Validate BCP 47 tag (zh-Hant-TW) — canonical form + regions
- [Line Deduper](https://devtools.surf/tools/line-dedupe): Collapse duplicate lines, show occurrence counts
- [Safe Filename Generator](https://devtools.surf/tools/safe-filename-generator): Strip accents + unsafe chars → filesystem-safe filename
- [ASCII Box Drawer](https://devtools.surf/tools/ascii-box-drawer): Wrap any text in a Unicode box (┌─┐) — great for READMEs
- [Text Reverser](https://devtools.surf/tools/text-reverser): Reverse a string — emoji-safe (operates on grapheme clusters)
- [Email Extractor](https://devtools.surf/tools/email-extractor): Extract every unique email address from a blob of text
- [URL Extractor](https://devtools.surf/tools/url-extractor): Extract every unique http/https URL from a blob of text
- [Text Repeater](https://devtools.surf/tools/text-repeater): Repeat text N times with a custom separator — newline, space, emoji
- [Title Case Converter](https://devtools.surf/tools/title-case-converter): Capitalize words — AP-style, keep small words lowercase unless first/last
- [Whitespace Normalizer](https://devtools.surf/tools/whitespace-normalizer): Collapse runs of spaces/tabs, trim lines, drop consecutive blanks
- [Tab ↔ Space Converter](https://devtools.surf/tools/tab-space-converter): Switch tabs to N spaces or N spaces back to tabs
- [Line Break Converter](https://devtools.surf/tools/line-break-converter): Normalize CRLF / LF / CR line endings across an entire file
- [Line Shuffler](https://devtools.surf/tools/line-shuffler): Randomly shuffle every line in your input — Fisher-Yates, deterministic
- [Syllable Counter](https://devtools.surf/tools/syllable-counter): Count syllables per word — heuristic-based English estimator
- [Pig Latin Converter](https://devtools.surf/tools/pig-latin-converter): Translate English text to pig latin — keeps case, punctuation intact
- [Bold Text Generator](https://devtools.surf/tools/bold-text-generator): Turn regular text into unicode 𝐛𝐨𝐥𝐝 — works in bios, Slack, Discord
- [Italic Text Generator](https://devtools.surf/tools/italic-text-generator): Turn regular text into unicode 𝑖𝑡𝑎𝑙𝑖𝑐 — copy/paste anywhere
- [Strikethrough Text Generator](https://devtools.surf/tools/strikethrough-text-generator): Add combining-mark s̶t̶r̶i̶k̶e̶ to any text — no markdown needed
- [Fancy Text Generator](https://devtools.surf/tools/fancy-text-generator): 8 unicode style variants — bold, italic, script, fraktur, monospace and more
- [Upside-Down Text](https://devtools.surf/tools/upside-down-text): Flip text upside-down using unicode substitutions — ǝpɐɯ ʞlıɯ
- [Small Caps Converter](https://devtools.surf/tools/small-caps-converter): Convert normal text to sᴍᴀʟʟ ᴄᴀᴘs — pure unicode, no CSS
- [Circled Text Generator](https://devtools.surf/tools/circled-text-generator): Render letters + digits as ⒸⒾⓇⒸⓁⒺⒹ unicode glyphs
- [Square Text Generator](https://devtools.surf/tools/square-text-generator): Render letters as 🅂🅀🅄🄰🅁🄴🄳 unicode glyphs for banners and bios
- [Superscript & Subscript](https://devtools.surf/tools/superscript-subscript): Convert letters/digits to ˢᵘᵖᵉʳ or ₛᵤᵦ script — CO₂, H₂O, x²
- [Emoji Letter Mapper](https://devtools.surf/tools/emoji-letter-mapper): Replace letters with regional-indicator and symbol emoji
- [Vaporwave Text](https://devtools.surf/tools/vaporwave-text): Convert ASCII to ｆｕｌｌｗｉｄｔｈ aesthetic letters — vaporwave vibes
- [Cursed Text Generator](https://devtools.surf/tools/cursed-text-generator): Stack combining marks above/below letters for a glitchy, cursed look
- [Wide Text Generator](https://devtools.surf/tools/wide-text-generator): Add spaces between every character for a stretched / wide look

### Encoding

- [Base64 Encode](https://devtools.surf/tools/base64-encode): Encode text or files to Base64
- [Base64 Decode](https://devtools.surf/tools/base64-decode): Decode Base64 back to text or file
- [Hash Generator](https://devtools.surf/tools/hash-generator): Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text
- [Number Base Converter](https://devtools.surf/tools/number-base-converter): Convert between decimal, hex, octal, and binary
- [Timestamp Converter](https://devtools.surf/tools/timestamp-converter): Convert between Unix epoch, ISO 8601, and human-readable dates
- [Base58/Base32/Base85](https://devtools.surf/tools/base58-encoder): Encode and decode text in Base58, Base32, or Base85
- [Base64URL Encoder](https://devtools.surf/tools/base64url-encoder): URL-safe base64 — + → - , / → _ , no padding
- [Base64URL Decoder](https://devtools.surf/tools/base64url-decoder): Decode URL-safe base64 back to UTF-8 text
- [Text ↔ Binary](https://devtools.surf/tools/text-to-binary): Convert UTF-8 text to 0/1 binary — or decode back
- [Text ↔ Hex](https://devtools.surf/tools/text-to-hex): UTF-8 text to hexadecimal bytes — or decode hex back to text
- [Text ↔ Octal](https://devtools.surf/tools/text-to-octal): UTF-8 text to octal digit sequences — or decode octal back
- [ASCII85 Encoder](https://devtools.surf/tools/ascii85-encoder): Adobe ASCII85 (base85) for compact binary in PDF/PostScript payloads

### Generators

- [UUID Generator](https://devtools.surf/tools/uuid-generator): Generate v4 UUIDs — single or bulk
- [ULID Generator](https://devtools.surf/tools/ulid-generator): Generate sortable ULIDs (Universally Unique Lexicographically Sortable IDs)
- [Password Generator](https://devtools.surf/tools/password-generator): Generate secure random passwords with custom rules
- [cURL to Code](https://devtools.surf/tools/curl-to-code): Convert cURL commands to fetch, axios, Python requests, and more
- [Cron Expression Parser](https://devtools.surf/tools/cron-expression-parser): Describe cron expressions in plain English with next run times
- [SQL Formatter](https://devtools.surf/tools/sql-formatter): Format and prettify SQL queries
- [GraphQL Formatter](https://devtools.surf/tools/graphql-formatter): Format and prettify GraphQL queries and schemas
- [JSON Schema Generator](https://devtools.surf/tools/json-schema-generator): Generate JSON Schema from a sample JSON object
- [TypeScript Interface Generator](https://devtools.surf/tools/ts-interface-generator): Generate TypeScript interfaces from JSON data
- [Mock Data Generator](https://devtools.surf/tools/mock-data-generator): Generate fake names, emails, addresses, and more in JSON or CSV
- [QR Code Generator](https://devtools.surf/tools/qr-code-generator): Generate QR codes from text or URLs
- [Chmod Calculator](https://devtools.surf/tools/chmod-calculator): Convert between symbolic and numeric Unix file permissions
- [.gitignore Builder](https://devtools.surf/tools/gitignore-builder): Build a .gitignore from curated language/framework templates
- [Unix Cron Visualizer](https://devtools.surf/tools/unix-cron-visualizer): Visualize cron schedules as a timeline of next executions
- [Chmod → English](https://devtools.surf/tools/chmod-to-english): Convert numeric chmod values to human-readable permission descriptions
- [Privacy Policy Generator](https://devtools.surf/tools/privacy-policy-generator): Generate a privacy policy from your app name, URL, and data practices
- [Crontab Generator](https://devtools.surf/tools/crontab-generator): Build cron schedules visually with dropdowns for each field
- [Random String Generator](https://devtools.surf/tools/random-string-generator): Secure random strings — hex, base64, base58, symbols, custom length
- [Fake Name Generator](https://devtools.surf/tools/fake-name-generator): Bulk fake first+last names for test fixtures — famous tech names pool
- [Fake Address Generator](https://devtools.surf/tools/fake-address-generator): Bulk US-style fake addresses for seeding dev databases
- [Fake Phone Generator](https://devtools.surf/tools/fake-phone-generator): Bulk fake phone numbers in US / UK / E.164 formats
- [Test Credit Card Generator](https://devtools.surf/tools/test-credit-card-generator): Luhn-valid dev cards for Visa/MC/Amex/Discover/JCB/Diners
- [Test IBAN Generator](https://devtools.surf/tools/iban-test-generator): Synthesize IBANs with valid ISO 13616 checksums per country
- [Test VIN Generator](https://devtools.surf/tools/vin-generator): Random 17-char VINs with valid position-9 check digit
- [Barcode Generator](https://devtools.surf/tools/barcode-generator): Generate CODE-128 barcode PNGs from any text — client-side canvas
- [Data URI Generator](https://devtools.surf/tools/data-uri-generator): Wrap any text (or file contents) into a base64 data: URI
- [API Key Generator](https://devtools.surf/tools/api-key-generator): Secure random API keys with prefix (sk_, pk_, whsec_) — base62 or hex
- [Bcrypt Demo Hash](https://devtools.surf/tools/bcrypt-generator): Generate a bcrypt-style hash preview — configurable cost rounds (4-14)
- [Argon2 Demo Hash](https://devtools.surf/tools/argon2-generator): Generate an argon2id PHC-formatted hash preview for docs / fixtures
- [Shield Badge Generator](https://devtools.surf/tools/shield-badge-generator): Build Shields.io README badges — label, message, color, logo, style
- [README.md Generator](https://devtools.surf/tools/readme-md-generator): Starter README template with title, description, install, usage, license
- [.editorconfig Generator](https://devtools.surf/tools/editorconfig-generator): Tab/space indent, EOL, charset rules — one config for every editor
- [.prettierrc Generator](https://devtools.surf/tools/prettier-config): Build a Prettier config — semi, quote style, trailing comma, width
- [.eslintrc Generator](https://devtools.surf/tools/eslint-config): ESLint config for Node / TypeScript / React — commonjs output
- [CHANGELOG.md Generator](https://devtools.surf/tools/changelog-md-generator): Keep a Changelog starter with [Unreleased] + first version section
- [LICENSE File Generator](https://devtools.surf/tools/license-file-generator): MIT, Apache 2.0, BSD 3-Clause, GPL 3.0, Unlicense — year + holder
- [Dockerfile Generator](https://devtools.surf/tools/dockerfile-generator): Multi-stage Dockerfile for Node / Python / Go — production-ready
- [docker-compose.yml Generator](https://devtools.surf/tools/docker-compose-generator): Wire up api + postgres + redis + mongo into a single compose file
- [Makefile Generator](https://devtools.surf/tools/makefile-generator): Language-aware Makefile for Node / Python / Go — install/dev/test/build
- [.gitignore Templates](https://devtools.surf/tools/gitignore-templates): Combine templates — node, python, go, rust, java, macos, windows, vscode
- [Passphrase Generator (EFF)](https://devtools.surf/tools/passphrase-generator): Memorable multi-word passphrases from a 300-word EFF-style list

### Color

- [Color Converter](https://devtools.surf/tools/color-converter): Convert between HEX, RGB, HSL, OKLCH, and Tailwind colors
- [Color Palette Generator](https://devtools.surf/tools/color-palette-generator): Generate complementary, analogous, and triadic color palettes
- [Contrast Checker](https://devtools.surf/tools/contrast-checker): Check WCAG AA/AAA contrast ratio between two colors
- [Gradient Generator](https://devtools.surf/tools/gradient-generator): Design CSS/SVG gradients and export as CSS, SVG, or Figma tokens
- [Color Contrast Matrix](https://devtools.surf/tools/color-contrast-matrix): Test WCAG contrast ratios for every color pair in a palette
- [Hex → Tailwind](https://devtools.surf/tools/colors-to-tailwind): Map a hex/rgb color to the nearest Tailwind class
- [Gradient → Code](https://devtools.surf/tools/gradient-to-code): Translate a CSS gradient into SwiftUI, Android, and Flutter code
- [Color Name Finder](https://devtools.surf/tools/color-name-finder): Closest CSS named color to any hex (Euclidean in RGB)
- [Color Scheme Generator](https://devtools.surf/tools/color-scheme-generator): Complementary, analogous, triadic, tetradic & split-comp schemes from a base color
- [Tailwind Color Palette](https://devtools.surf/tools/tailwind-color-palette): Full Tailwind CSS v3 color palette — 18 families × 11 shades, searchable
- [Material Color Palette](https://devtools.surf/tools/material-color-palette): Google Material 2014 palette — families with 50–900 + A100–A700 shades
- [CSS Named Colors](https://devtools.surf/tools/css-named-colors): All 147 CSS named colors with hex values — instantly searchable
- [Color Shades & Tints](https://devtools.surf/tools/color-shades-tints): Generate 9 darker shades + 9 lighter tints from any base color
- [Complementary Colors](https://devtools.surf/tools/complementary-colors): Find the opposite color on the wheel — 180° hue rotation
- [Analogous Colors](https://devtools.surf/tools/analogous-colors): Colors adjacent on the wheel (±30°) — gentle, harmonious palettes
- [Triadic Colors](https://devtools.surf/tools/triadic-colors): Three colors equally spaced on the wheel (120°) — vivid & balanced
- [Tetradic Colors](https://devtools.surf/tools/tetradic-colors): Four colors at 90° — two complementary pairs for rich palettes
- [Monochromatic Colors](https://devtools.surf/tools/monochromatic-colors): Single-hue palette — nine lightness steps at the same saturation
- [Random Color Generator](https://devtools.surf/tools/random-color-generator): Bulk random colors (hex/rgb/hsl) — great for placeholders & mocks
- [Color Mixer](https://devtools.surf/tools/color-mixer): Blend 2+ colors using perceptual square-mean RGB (not linear RGB mud)
- [Color Lighten / Darken](https://devtools.surf/tools/color-lighten-darken): Shift a color's lightness by +/- N%, preserving hue & saturation
- [Color Temperature (Kelvin)](https://devtools.surf/tools/color-kelvin-converter): Convert 1000–40000K to an RGB approximation (Tanner Helland formula)
- [Pantone Reference](https://devtools.surf/tools/pantone-reference): Search common Pantone PMS spot colors with sRGB approximations

### Networking

- [IP Address Lookup](https://devtools.surf/tools/ip-address-lookup): Parse and validate IPv4/IPv6 addresses and CIDR ranges
- [HTTP Status Reference](https://devtools.surf/tools/http-status-reference): Quick lookup of HTTP status codes and their meanings
- [DNS Record Explainer](https://devtools.surf/tools/dns-record-explainer): Explain A, AAAA, CNAME, MX, TXT, SRV and other DNS records
- [WebSocket Frame Decoder](https://devtools.surf/tools/websocket-frame-decoder): Decode WebSocket frame headers and payloads from hex
- [Port Reference Lookup](https://devtools.surf/tools/port-reference-lookup): Look up common services for any TCP/UDP port number
- [MIME Type Lookup](https://devtools.surf/tools/mime-type-lookup): Convert between file extensions and MIME types
- [Certificate Decoder](https://devtools.surf/tools/cert-decoder): Decode X.509 PEM certificates into readable fields
- [HPKP Generator](https://devtools.surf/tools/hpkp-generator): Generate HTTP Public Key Pinning headers from a certificate
- [User-Agent Parser](https://devtools.surf/tools/user-agent-parser): Parse browser, OS, device from a User-Agent string
- [CORS Header Tester](https://devtools.surf/tools/cors-header-tester): Analyze CORS response headers for misconfigurations and security issues
- [CIDR Calculator](https://devtools.surf/tools/cidr-calculator): Calculate network address, broadcast, host range from CIDR notation
- [HTTP Header Analyzer](https://devtools.surf/tools/http-header-analyzer): Analyze HTTP headers for security, caching, and best practices
- [MAC Address Lookup (OUI)](https://devtools.surf/tools/mac-address-lookup): Identify the manufacturer from a MAC address OUI prefix
- [HTTP Method Reference](https://devtools.surf/tools/http-method-reference): Quick reference for all HTTP methods with use cases and safety info
- [Query String Builder](https://devtools.surf/tools/query-string-builder): Build ?k=v&k=v strings from key=value lines — repeating keys OK
- [Basic Auth Generator](https://devtools.surf/tools/basic-auth-generator): Base64-encode user:pass into an HTTP Basic Authorization header
- [Bearer Token Builder](https://devtools.surf/tools/bearer-token-builder): Wrap a raw token in HTTP Authorization + curl + fetch snippets
- [HTTP Header Builder](https://devtools.surf/tools/http-header-builder): Compose request headers — output as curl flags and fetch options
- [Subnet Calculator (v2)](https://devtools.surf/tools/subnet-calculator-v2): CIDR → subnet mask, network, broadcast, first/last host, host count
- [IPv6 Expander](https://devtools.surf/tools/ipv6-expander): Expand ::abbreviated IPv6 and also emit the canonical compressed form
- [IPv4 → IPv6 Mapper](https://devtools.surf/tools/ipv4-ipv6-converter): IPv4-mapped IPv6 address (::ffff:a.b.c.d) — RFC 4291 representation
- [RFC Lookup](https://devtools.surf/tools/rfc-lookup): Search 25+ foundational RFCs by number, title, or topic
- [Well-Known Ports](https://devtools.surf/tools/well-known-ports): 40+ standard TCP/UDP ports — search by number, service, or keyword

### PDF

- [Sample PDFs](https://devtools.surf/tools/sample-pdfs): Download ready-made sample PDFs of various sizes and page counts
- [PDF Merger](https://devtools.surf/tools/pdf-merger): Merge multiple PDFs into a single document
- [PDF Splitter](https://devtools.surf/tools/pdf-splitter): Split a PDF by page ranges
- [PDF Compressor](https://devtools.surf/tools/pdf-compressor): Reduce PDF file size in the browser
- [Markdown → PDF](https://devtools.surf/tools/markdown-to-pdf): Write or paste Markdown and export it as a downloadable PDF
- [Invoice Generator](https://devtools.surf/tools/invoice-generator): Create professional invoices from line items and export as PDF

### API / Config

- [REST Handler](https://devtools.surf/tools/rest-handler): Lightweight REST client — collections, env vars, history, format converter (cURL / Collection JSON / REST Handler YAML)
- [OpenAPI Viewer](https://devtools.surf/tools/openapi-viewer): Browse endpoints, schemas, and operations from an OpenAPI 3 spec
- [Swagger to Collection JSON](https://devtools.surf/tools/swagger-to-collection): Convert an OpenAPI / Swagger spec into a Collection JSON v2.1 payload
- [package.json Analyzer](https://devtools.surf/tools/package-json-analyzer): Detect duplicate dependencies and common issues
- [Dockerfile Linter](https://devtools.surf/tools/dockerfile-linter): Check Dockerfiles against common best practices
- [Kubernetes Manifest Validator](https://devtools.surf/tools/k8s-manifest-validator): Validate required fields in Kubernetes YAML manifests
- [Mock Server Config Generator](https://devtools.surf/tools/mock-server-config): Generate stub responses from a JSON Schema

### Date / Time

- [Timezone Converter](https://devtools.surf/tools/timezone-converter): Convert a date-time between multiple timezones
- [Duration Calculator](https://devtools.surf/tools/duration-calculator): Calculate the duration between two dates or times
- [Age Calculator](https://devtools.surf/tools/age-calculator): Calculate exact age in years, months, and days from a birthdate
- [Working Day Calculator](https://devtools.surf/tools/working-day-calculator): Count business days between two dates (excluding weekends)
- [Week Number Lookup](https://devtools.surf/tools/week-number-lookup): Find the ISO week number for any date
- [Date Offset Calculator](https://devtools.surf/tools/date-offset): Add/subtract days, weeks, months, years with weekday result
- [Cron Humanizer](https://devtools.surf/tools/cron-humanizer): Explain a cron expression in English + show the next 5 run times
- [Date Format Converter](https://devtools.surf/tools/date-format-converter): Show the same instant in ISO, RFC-2822, epoch, DD/MM/YYYY and more
- [Countdown Timer Builder](https://devtools.surf/tools/countdown-timer-builder): Build a live <div>-and-JS countdown to any ISO target timestamp
- [Pomodoro Timer Planner](https://devtools.surf/tools/pomodoro-timer): Plan a 25/5 Pomodoro session with long break — outputs a timeline
- [ICS Calendar Event Generator](https://devtools.surf/tools/ics-event-generator): Build a standards-compliant .ics event file — import to any calendar
- [ISO 8601 Duration Parser](https://devtools.surf/tools/iso-duration-parser): Parse P3Y6M4DT12H30M5S into years, months, weeks, days, time
- [Date Range Generator](https://devtools.surf/tools/date-range-generator): List every date between start and end — step N days/weeks/months
- [Weekday Calendar](https://devtools.surf/tools/weekday-calendar): Render a month-at-a-glance calendar grid — YYYY-MM input

### Security / Crypto

- [JWT Encoder](https://devtools.surf/tools/jwt-encoder): Encode a JWT token from header, payload, and secret
- [Bcrypt Hash Tester](https://devtools.surf/tools/bcrypt-hash-tester): Generate bcrypt hashes and verify passwords against hashes
- [HMAC Generator](https://devtools.surf/tools/hmac-generator): Generate HMAC signatures using SHA-256, SHA-512, and more
- [Password Strength Analyzer](https://devtools.surf/tools/password-strength-analyzer): Analyze password strength with entropy and crack-time estimates
- [TOTP / 2FA Generator](https://devtools.surf/tools/totp-generator): Generate time-based one-time passwords from a secret key
- [SAML Response Decoder](https://devtools.surf/tools/saml-decoder): Decode Base64-encoded SAML responses into readable XML
- [OAuth PKCE Generator](https://devtools.surf/tools/oauth-pkce-generator): Generate code_verifier, code_challenge, and state for OAuth PKCE flows
- [SSH Key Fingerprint](https://devtools.surf/tools/ssh-key-fingerprint): Calculate the fingerprint of an SSH public key
- [CSR Decoder](https://devtools.surf/tools/csr-decoder): Decode PEM-encoded Certificate Signing Requests
- [Secrets Scanner](https://devtools.surf/tools/secrets-scanner): Scan text/code for leaked API keys, tokens, and credentials
- [RSA Keypair Generator](https://devtools.surf/tools/rsa-keypair-generator): Generate RSA public/private keypairs in PEM format
- [JWT Timeline](https://devtools.surf/tools/jwt-timeline): Decode JWT + show iat / nbf / exp as ISO + delta from now
- [AES Encrypt / Decrypt](https://devtools.surf/tools/aes-encrypt-decrypt): AES-256-GCM encryption with authenticated ciphertext (iv:tag:body)
- [ROT13 Cipher](https://devtools.surf/tools/rot13-cipher): Classic Caesar-13 substitution — encrypt and decrypt are the same op
- [Caesar Cipher](https://devtools.surf/tools/caesar-cipher): Shift letters by any N positions (±26) — enc/dec with custom shift
- [Vigenère Cipher](https://devtools.surf/tools/vigenere-cipher): Polyalphabetic cipher using a keyword — stronger than Caesar
- [Atbash Cipher](https://devtools.surf/tools/atbash-cipher): Hebrew alphabet substitution — A↔Z, B↔Y — self-inverse
- [Rail Fence Cipher](https://devtools.surf/tools/rail-fence-cipher): Transposition cipher in a zig-zag pattern across N rails — enc/dec

### Web / Frontend

- [Meta Tags / OG Previewer](https://devtools.surf/tools/meta-tag-previewer): Preview how meta tags and OpenGraph data appear on social platforms
- [Tailwind → CSS](https://devtools.surf/tools/tailwind-to-css): Convert Tailwind CSS classes to vanilla CSS properties
- [HTML → React JSX](https://devtools.surf/tools/html-to-jsx): Convert HTML to valid React JSX syntax
- [HTML → Markdown](https://devtools.surf/tools/html-to-markdown): Convert HTML content to Markdown format
- [SVG → React Component](https://devtools.surf/tools/svg-to-react): Convert SVG markup into a React component
- [CSS Unit Converter](https://devtools.surf/tools/css-unit-converter): Convert between px, rem, em, vw, vh, and other CSS units
- [robots.txt Validator](https://devtools.surf/tools/robots-txt-validator): Validate robots.txt syntax and check for common issues
- [Sitemap XML Validator](https://devtools.surf/tools/sitemap-validator): Validate sitemap.xml structure and check for common issues
- [RSS/Atom Feed Validator](https://devtools.surf/tools/rss-feed-validator): Validate RSS 2.0 and Atom feed XML structure
- [CSS Box Shadow Builder](https://devtools.surf/tools/css-box-shadow-builder): Generate CSS box-shadow values from parameters
- [CSS Clip-Path Builder](https://devtools.surf/tools/css-clip-path-builder): Generate CSS clip-path polygon values
- [Flexbox Playground](https://devtools.surf/tools/flexbox-playground): Generate CSS flexbox layouts from property combinations
- [Cubic Bezier Editor](https://devtools.surf/tools/cubic-bezier-editor): Generate CSS cubic-bezier timing functions from control points
- [Accessibility Auditor](https://devtools.surf/tools/a11y-auditor): Check HTML for common accessibility issues (ARIA, alt text, headings)
- [Structured Data Tester](https://devtools.surf/tools/structured-data-tester): Validate JSON-LD schema.org structured data
- [OpenGraph Image Debugger](https://devtools.surf/tools/og-image-debugger): Validate OpenGraph meta tags and preview how URLs appear when shared
- [Sitemap Generator](https://devtools.surf/tools/sitemap-generator): Generate sitemap.xml from a list of URLs with priority and frequency
- [Favicon Checker](https://devtools.surf/tools/favicon-checker): Validate favicon HTML tags and preview all icon sizes
- [px ↔ rem Table](https://devtools.surf/tools/px-rem-table): Generate a pixel-to-rem scale table for a chosen base size
- [URL Parser](https://devtools.surf/tools/url-parser): Break a URL into scheme, host, path, query, fragment
- [Query String → JSON](https://devtools.surf/tools/query-string-to-json): Turn ?a=1&b=foo into a flat JSON object
- [Cookie Parser](https://devtools.surf/tools/cookie-parser): Parse Cookie / Set-Cookie header into name=value + attribute list
- [HTTP Header Inspector](https://devtools.surf/tools/http-header-inspector): Pretty-print raw HTTP headers with inline meanings

### Data / SQL

- [CSV Viewer](https://devtools.surf/tools/csv-viewer): View CSV data in a sortable, filterable table
- [CSV → SQL INSERT](https://devtools.surf/tools/csv-to-sql-insert): Generate SQL INSERT statements from CSV data
- [SQL → CSV Fixture](https://devtools.surf/tools/sql-to-csv): Convert SQL INSERT statements to CSV format
- [TSV ↔ CSV](https://devtools.surf/tools/tsv-csv-converter): Convert between tab-separated and comma-separated values
- [CSV Schema Validator](https://devtools.surf/tools/csv-schema-validator): Validate CSV data against a column schema definition
- [SQL → Prisma Schema](https://devtools.surf/tools/sql-to-prisma): Convert SQL CREATE TABLE statements to Prisma schema
- [CSV Column Remapper](https://devtools.surf/tools/csv-column-remapper): Rename, reorder, or drop columns in CSV data
- [CSV Validator with Schema](https://devtools.surf/tools/csv-validator-schema): Validate CSV data against column type definitions
- [SQL Identifier Caser](https://devtools.surf/tools/sql-case-mapper): Convert SQL identifiers between snake, camel, and Pascal case
- [Column Extract](https://devtools.surf/tools/column-extract): Pull the Nth whitespace-delimited column from each line

### AI / Modern Dev

- [Token Counter](https://devtools.surf/tools/token-counter): Estimate token count for OpenAI and Anthropic models
- [Prompt Template Renderer](https://devtools.surf/tools/prompt-template-renderer): Render prompt templates with variable substitution
- [Markdown → Slack/Discord](https://devtools.surf/tools/markdown-to-slack): Convert Markdown to Slack mrkdwn or Discord formatting
- [Embedding Distance Calculator](https://devtools.surf/tools/embedding-distance): Calculate cosine similarity between two text embedding vectors
- [Markdown → Slack mrkdwn](https://devtools.surf/tools/slack-mrkdwn): Convert GitHub-flavor markdown to Slack's mrkdwn

### Fun / Niche

- [Emoji / Unicode Lookup](https://devtools.surf/tools/emoji-unicode-lookup): Search emoji by name and show Unicode codepoints
- [NATO Phonetic Alphabet](https://devtools.surf/tools/nato-phonetic): Convert text to NATO phonetic alphabet spelling
- [Morse Code ↔ Text](https://devtools.surf/tools/morse-code): Convert text to Morse code and back
- [Roman Numeral Converter](https://devtools.surf/tools/roman-numeral-converter): Convert between Roman numerals and decimal numbers
- [Number → Words](https://devtools.surf/tools/number-to-words): Convert numbers to written English words
- [Leet Speak ↔ Plain](https://devtools.surf/tools/leet-speak): Convert text to/from 1337 speak
- [Slug Generator](https://devtools.surf/tools/slug-generator): Generate URL-friendly slugs from text
- [Zero-Width Character Detector](https://devtools.surf/tools/zero-width-detector): Find and highlight invisible zero-width characters in text
- [Smart Quotes Fixer](https://devtools.surf/tools/smart-quotes-fixer): Replace curly/smart quotes with straight quotes and vice versa
- [Text Similarity Scorer](https://devtools.surf/tools/text-similarity-scorer): Calculate similarity between two text strings (Levenshtein, Jaccard)
- [ISBN/IBAN/Luhn Validator](https://devtools.surf/tools/isbn-iban-validator): Validate ISBN, IBAN, and credit card numbers (Luhn check)
- [ASCII Table Reference](https://devtools.surf/tools/ascii-table-reference): Browse the full ASCII table with decimal, hex, and character values
- [Bionic Reading Converter](https://devtools.surf/tools/bionic-reading): Bold the first half of each word for faster reading
- [Anagram Finder](https://devtools.surf/tools/anagram-finder): Check if two strings are anagrams and show letter frequency
- [Braille ↔ Text](https://devtools.surf/tools/braille-converter): Convert text to Braille Unicode characters and back
- [Color Blindness Simulator](https://devtools.surf/tools/color-blindness-simulator): Simulate how hex colors appear under different color blindness types
- [User Input Fuzzer](https://devtools.surf/tools/user-input-fuzzer): Generate edge-case test inputs for form validation testing
- [Palindrome Checker](https://devtools.surf/tools/palindrome-checker): Test if text reads the same forward & backward
- [Haiku Counter](https://devtools.surf/tools/haiku-counter): Check a poem fits the 5-7-5 syllable pattern
- [Emoji Counter](https://devtools.surf/tools/emoji-counter): Count and group emoji present in any text
- [Zalgo Text](https://devtools.surf/tools/zalgo-generator): Corrupt normal text with diacritical fury for fun
- [SpongeBob Case](https://devtools.surf/tools/spongebob-case): aLtErNaTiNg cAsE gEnErAtOr — memes only
- [Dice Roller](https://devtools.surf/tools/dice-notation-roller): Roll standard RPG dice notation — 3d6+2, 2d20-1, mixed
- [Age on Other Planets](https://devtools.surf/tools/age-in-planets): Convert your Earth age to Mercury, Venus, Mars, Jupiter … even Pluto
- [Coin Flip Simulator](https://devtools.surf/tools/coin-flip-simulator): Flip a fair coin N times — tallies + raw sequence. Optional seed.
- [Random List Picker](https://devtools.surf/tools/random-list-picker): Pick a winner from a list — shows the full shuffled order too
- [Decision Wheel](https://devtools.surf/tools/decision-wheel): Spin a wheel of N options and get the top 5 picks in random order
- [Fantasy Name Generator](https://devtools.surf/tools/fantasy-name-generator): Generate fantasy/elvish-style names for characters, towns, NPCs
- [Compound Word Finder](https://devtools.surf/tools/compound-word-finder): Split compound words (rainbow → rain+bow, moonlight → moon+light)
- [Word Scrambler](https://devtools.surf/tools/word-scrambler): Typoglycemia-style scramble: keep first+last letter, shuffle middle

### Developer Utilities

- [Collection JSON → cURL](https://devtools.surf/tools/collection-to-curl): Convert Collection JSON v2.1 requests into cURL one-liners
- [Git Diff → HTML](https://devtools.surf/tools/git-diff-to-html): Convert unified git diff output to syntax-highlighted HTML
- [Regex Visualizer](https://devtools.surf/tools/regex-visualizer): Visualize regex patterns as a readable railroad diagram (text)
- [Makefile Explainer](https://devtools.surf/tools/makefile-explainer): Parse a Makefile and explain each target and its dependencies
- [Shell Script Linter](https://devtools.surf/tools/shell-script-linter): Check shell scripts for common issues and bad practices
- [GitHub Actions Visualizer](https://devtools.surf/tools/github-actions-visualizer): Parse a GitHub Actions workflow and show job/step dependencies
- [HAR File Viewer](https://devtools.surf/tools/har-file-viewer): Parse and summarize HTTP Archive (HAR) files
- [API Response Mocker](https://devtools.surf/tools/api-response-mocker): Generate mock API JSON responses from a URL + method description
- [GraphQL Query Builder](https://devtools.surf/tools/graphql-query-builder): Generate GraphQL queries from a schema definition
- [OpenAPI → TypeScript](https://devtools.surf/tools/openapi-to-typescript): Generate TypeScript interfaces from an OpenAPI schema
- [Diff Patch Applier](https://devtools.surf/tools/diff-patch-applier): Apply a unified diff patch to source text
- [GraphQL Introspection → SDL](https://devtools.surf/tools/graphql-introspection-to-sdl): Convert GraphQL introspection JSON to SDL schema
- [HTTP Request Replayer](https://devtools.surf/tools/http-request-replayer): Generate fetch/axios/curl code from raw HTTP request text
- [cURL → fetch()](https://devtools.surf/tools/curl-to-fetch): Convert a curl command into a JS fetch() call
- [Git Log Parser](https://devtools.surf/tools/git-log-parser): Parse git log output into structured JSON
- [HTTP → cURL Builder](https://devtools.surf/tools/http-curl-builder): Build a curl command from method, URL, headers & body fields
- [SemVer Bump](https://devtools.surf/tools/semver-bump): Compute next major / minor / patch / prerelease
- [Apache/Nginx Log Parser](https://devtools.surf/tools/apache-log-parser): Parse combined log format lines into JSON (host, status, UA…)

### Game Dev

- [Unity C# Class Generator](https://devtools.surf/tools/unity-class-generator): Generate Unity MonoBehaviour, ScriptableObject, or Editor scripts from a template
- [Unity Prefab Inspector](https://devtools.surf/tools/unity-prefab-inspector): Parse and display Unity .prefab YAML structure in a readable format
- [Sprite Sheet Calculator](https://devtools.surf/tools/sprite-sheet-calculator): Calculate frame dimensions, UV coords, and animation timing from sprite sheet parameters
- [Game Math Calculator](https://devtools.surf/tools/game-math-calculator): Calculate vectors, distances, dot products, lerp, and common game math operations
- [Game Color Palette Generator](https://devtools.surf/tools/color-palette-game): Generate game-ready color palettes with hex, RGB, and normalized float values
- [Tilemap Data Generator](https://devtools.surf/tools/tilemap-generator): Generate 2D tilemap arrays for grid-based games from a visual text grid
- [Damage Formula Calculator](https://devtools.surf/tools/damage-formula-calculator): Calculate RPG damage with attack, defense, crit, elemental modifiers
- [Loot Table Generator](https://devtools.surf/tools/loot-table-generator): Generate weighted loot drop tables with probability calculations
- [Shader Uniform Generator](https://devtools.surf/tools/shader-uniform-generator): Generate GLSL/HLSL uniform declarations from parameter descriptions
- [Game Resolution Scaler](https://devtools.surf/tools/game-resolution-scaler): Calculate render resolutions, aspect ratios, and DPI for different platforms
- [FPS ↔ Frame Time Converter](https://devtools.surf/tools/fps-ms-converter): Convert between FPS and milliseconds per frame with performance budgets
- [Easing Function Generator](https://devtools.surf/tools/easing-function-generator): Generate easing functions in C#, GLSL, JS with visual curve preview
- [Game Event System Generator](https://devtools.surf/tools/game-event-system-generator): Generate event bus / observer pattern boilerplate for Unity, Godot, or JS
- [State Machine Generator](https://devtools.surf/tools/state-machine-generator): Generate finite state machine code from state/transition definitions
- [Platformer Physics Calculator](https://devtools.surf/tools/platformer-physics-calculator): Calculate jump height, gravity, velocity for platformer feel
- [Asset Bundle Size Estimator](https://devtools.surf/tools/asset-bundle-size-estimator): Estimate build sizes for textures, audio, meshes across platforms

### Animation / CSS

- [CSS Keyframe Generator](https://devtools.surf/tools/css-keyframe-generator): Generate @keyframes animations from step definitions
- [Loading Spinner Generator](https://devtools.surf/tools/loading-spinner-generator): Generate CSS-only loading spinners and progress indicators
- [Skeleton Screen Generator](https://devtools.surf/tools/skeleton-screen-generator): Generate shimmer skeleton placeholder CSS for loading states
- [Hover Effect Generator](https://devtools.surf/tools/hover-effect-generator): Generate CSS hover effects for buttons, cards, and links
- [CSS Transition Playground](https://devtools.surf/tools/css-transition-playground): Build and preview CSS transitions with property, duration, and easing controls
- [Text Animation Generator](https://devtools.surf/tools/text-animation-generator): Generate typewriter, fade-in, bounce, and other text animations
- [Scroll Animation Generator](https://devtools.surf/tools/scroll-animation-generator): Generate CSS scroll-triggered animation code with IntersectionObserver
- [Particle Effect Generator](https://devtools.surf/tools/particle-effect-generator): Generate CSS-only particle animations (confetti, snow, stars)
- [Gradient Animation Generator](https://devtools.surf/tools/gradient-animation-generator): Generate animated gradient backgrounds with CSS
- [Button Animation Generator](https://devtools.surf/tools/button-animation-generator): Generate animated button styles with ripple, glow, and morphing effects

### Calculators

- [Basic Calculator](https://devtools.surf/tools/basic-calculator): Evaluate math expressions with +, -, *, /, parentheses, and functions
- [Percentage Calculator](https://devtools.surf/tools/percentage-calculator): Calculate percentages, discounts, tips, and markup
- [Unit Converter](https://devtools.surf/tools/unit-converter-calc): Convert length, weight, temperature, speed, and data units
- [Loan / EMI Calculator](https://devtools.surf/tools/loan-calculator): Calculate monthly payments, total interest, and amortization
- [Number Formatter](https://devtools.surf/tools/number-formatter): Any number → grouped, compact, scientific, hex, binary, percent
- [Tip Calculator](https://devtools.surf/tools/tip-calculator): Quick tip + per-person split — US-style 15/18/20/22% presets
- [BMI Calculator](https://devtools.surf/tools/bmi-calculator): Body mass index with WHO categories — metric or imperial
- [Mortgage Calculator](https://devtools.surf/tools/mortgage-calculator): Monthly payment + total interest for any loan amount, rate, term
- [Compound Interest Calculator](https://devtools.surf/tools/compound-interest-calculator): Future value with configurable compounding + monthly contributions
- [Discount Calculator](https://devtools.surf/tools/discount-calculator): Final price after % off — plus total savings — for quick shopping math
- [Sales Tax Calculator](https://devtools.surf/tools/sales-tax-calculator): Add any % sales tax to a subtotal — breakdown + grand total
- [Gas Mileage Calculator](https://devtools.surf/tools/gas-mileage-calculator): MPG + L/100km + km/L — US or metric units in one calculator
- [Bill Splitter](https://devtools.surf/tools/bill-splitter): Split a bill evenly with tip + optional per-person rounding kitty
- [GPA Calculator](https://devtools.surf/tools/gpa-calculator): Compute unweighted 4.0 GPA from course | grade | credits lines
- [Temperature Converter](https://devtools.surf/tools/temperature-converter): Convert C / F / K / Rankine all at once — paste any of them

### Audio

- [Sample Audio Files](https://devtools.surf/tools/sample-audio): Download forest-ambience clips in WAV, MP3, Opus, FLAC, AAC, WebM
- [Audio Converter](https://devtools.surf/tools/audio-converter): Convert between WAV, MP3, Opus, AAC and more — 100% in-browser
- [Audio Merger](https://devtools.surf/tools/audio-merger): Join multiple clips back-to-back into one track
- [Audio Editor](https://devtools.surf/tools/audio-editor): Trim, fade, amplify, change speed — all client-side

### Cheatsheets

- [Git Cheatsheet](https://devtools.surf/tools/cheatsheet-git): Everyday Git commands — setup, commit, branch, remote, undo
- [Docker Cheatsheet](https://devtools.surf/tools/cheatsheet-docker): Docker + Compose commands for images, containers, volumes, Dockerfile
- [Regex Cheatsheet](https://devtools.surf/tools/cheatsheet-regex): Character classes, quantifiers, anchors, groups, flags
- [Markdown Cheatsheet](https://devtools.surf/tools/cheatsheet-markdown): CommonMark + GitHub-flavored Markdown syntax at a glance
- [Vim Cheatsheet](https://devtools.surf/tools/cheatsheet-vim): Modal editing essentials — modes, motions, edits, files
- [Bash / Shell Cheatsheet](https://devtools.surf/tools/cheatsheet-bash): Navigation, text processing, pipes, processes, scripting basics
- [SQL Cheatsheet](https://devtools.surf/tools/cheatsheet-sql): SELECT, JOIN, aggregates, window functions, upsert
- [kubectl Cheatsheet](https://devtools.surf/tools/cheatsheet-kubectl): Inspect, logs, apply, scale, context switching for Kubernetes
- [npm / yarn / pnpm Cheatsheet](https://devtools.surf/tools/cheatsheet-npm): Install, run, audit across all three package managers
- [TypeScript Cheatsheet](https://devtools.surf/tools/cheatsheet-typescript): Types, generics, utility types, narrowing, tsconfig essentials
- [CSS Flexbox Cheatsheet](https://devtools.surf/tools/cheatsheet-flexbox): Container + item props, common patterns (centered, sidebar, sticky footer)
- [CSS Grid Cheatsheet](https://devtools.surf/tools/cheatsheet-grid): Template, placement, auto-fit, named areas, holy grail
- [Tailwind CSS Cheatsheet](https://devtools.surf/tools/cheatsheet-tailwind): Layout, spacing, colors, variants, and pro tricks
- [Python Cheatsheet](https://devtools.surf/tools/cheatsheet-python): Collections, comprehensions, dataclasses, useful stdlib modules
- [JavaScript (ES2020+) Cheatsheet](https://devtools.surf/tools/cheatsheet-javascript): Destructuring, nullish, async, modern array methods, gotchas
- [React Hooks Cheatsheet](https://devtools.surf/tools/cheatsheet-react-hooks): State, memo, effects, context, custom hooks, newer APIs
- [Nginx Cheatsheet](https://devtools.surf/tools/cheatsheet-nginx): Reverse proxy, static + SPA fallback, HTTPS, ops commands
- [SSH Cheatsheet](https://devtools.surf/tools/cheatsheet-ssh): Keys, connect, port forwarding, ~/.ssh/config, file transfer
- [tmux Cheatsheet](https://devtools.surf/tools/cheatsheet-tmux): Sessions, windows, panes, copy mode for persistent terminals
- [cURL Cheatsheet](https://devtools.surf/tools/cheatsheet-curl): HTTP from the CLI — methods, headers, auth, timing, retries
- [Makefile Cheatsheet](https://devtools.surf/tools/cheatsheet-makefile): Rule basics, variables, pattern rules, and make invocations
- [HTTP Headers Cheatsheet](https://devtools.surf/tools/cheatsheet-http-headers): Request + response headers and a caching decision tree
- [LLM Prompting Cheatsheet](https://devtools.surf/tools/cheatsheet-llm-prompting): Techniques that actually help LLM output; anti-patterns to skip
- [JWT Cheatsheet](https://devtools.surf/tools/cheatsheet-jwt): Structure, standard claims, algorithms, do/don't
- [PostgreSQL Cheatsheet](https://devtools.surf/tools/cheatsheet-postgres): psql meta-commands, JSONB, indexing, EXPLAIN

### Info / Guides

- [Docker Basics](https://devtools.surf/tools/info-docker-basics): What containers are, why they're useful, first run, common pitfalls
- [SEO Basics for Developers](https://devtools.surf/tools/info-seo-basics): Technical SEO, on-page signals, structured data, what to skip
- [REST API Basics](https://devtools.surf/tools/info-rest-api-basics): HTTP verbs, status codes, resource naming, common gotchas
- [Next.js App Router Basics](https://devtools.surf/tools/info-nextjs-app-router-basics): File conventions, server vs client, data fetching, snags
- [Connect Your Site to Google](https://devtools.surf/tools/info-google-setup): Search Console, GA4, Tag Manager, Ads — end-to-end setup order
- [Git Basics (First Hour)](https://devtools.surf/tools/info-git-basics): Mental model, first workflow, daily loop, undo cookbook
- [Kubernetes Basics](https://devtools.surf/tools/info-kubernetes-basics): Pods, deployments, services, YAML, when to reach for k8s
- [GraphQL vs REST](https://devtools.surf/tools/info-graphql-vs-rest): When each wins, and the hidden costs of GraphQL at scale
- [WebSockets Basics](https://devtools.surf/tools/info-websockets-basics): Lifecycle, browser API, when to use, production gotchas
- [OAuth 2.0 Flows Explained](https://devtools.surf/tools/info-oauth2-flows): Auth code + PKCE, client credentials, device, token types, scopes
- [TLS / HTTPS Basics](https://devtools.surf/tools/info-tls-https-basics): Handshake, certs, Let's Encrypt, hardening to A+
- [Core Web Vitals](https://devtools.surf/tools/info-core-web-vitals): LCP, INP, CLS — what they are, how to fix, how to measure
- [CORS Explained](https://devtools.surf/tools/info-cors-explained): Same-origin rule, simple vs preflight, server headers, gotchas
- [Cookies vs localStorage vs sessionStorage](https://devtools.surf/tools/info-cookies-storage): Lifetime, security, cross-tab, cookie attributes, anti-patterns
- [Monorepos (Turbo / Nx / pnpm)](https://devtools.surf/tools/info-monorepos): When to monorepo, tool choice, pitfalls
- [Redis Basics](https://devtools.surf/tools/info-redis-basics): Data types, caching pattern, operational commands, pitfalls
- [PostgreSQL Basics](https://devtools.surf/tools/info-postgres-basics): Why Postgres, first queries, unique features, beginner mistakes
- [CI/CD with GitHub Actions (Basics)](https://devtools.surf/tools/info-github-actions): Anatomy, minimal workflow, triggers, secrets, deploy gotchas
- [Serverless vs Containers vs VMs](https://devtools.surf/tools/info-serverless-vs-containers): Where each wins; when serverless bites
- [Microservices vs Monolith](https://devtools.surf/tools/info-microservices-vs-monolith): Default to monolith; when to split; the modular-monolith middle path
- [DNS Basics](https://devtools.surf/tools/info-dns-basics): Record types, resolution, debugging, common snags
- [Load Balancing Basics](https://devtools.surf/tools/info-load-balancing): L4 vs L7, algorithms, health checks, failure modes
- [Caching Strategies](https://devtools.surf/tools/info-caching-strategies): Where to cache, patterns, invalidation, common bugs
- [Observability: Logs, Metrics, Traces](https://devtools.surf/tools/info-observability): Three pillars, RED/USE metrics, OpenTelemetry, tooling
- [SemVer & Dependency Hygiene](https://devtools.surf/tools/info-semver-dependencies): Version ranges, lockfile, update strategy, supply-chain hygiene

## Optional

- [Sitemap](https://devtools.surf/sitemap.xml)
- [Privacy policy](https://devtools.surf/privacy)
- [Community feed](https://devtools.surf/feed)
- [Themes](https://devtools.surf/themes)
- [Pricing](https://devtools.surf/payments)