About JSON Formatter

Format and prettify JSON with syntax highlighting. Part of the DevTools Surf developer suite. Browse more tools in the JSON collection.

Use Cases

• Prettify minified API responses for debugging
• Format config files before committing to git
• Clean up messy JSON from copy-paste
• Validate and fix JSON from legacy systems

Tips

• Paste relaxed JSON with comments, single quotes, or trailing commas — it auto-fixes them
• Use the indent pills to switch between 2-space, 4-space, tab, or minified
• Enable 'Sort keys' to alphabetize all object keys recursively

Fun Facts

• JSON was inspired by JavaScript object literals but is actually language-independent. Douglas Crockford popularized it in 2001.
• The entire JSON grammar can be expressed in just 6 railroad diagrams — it is one of the simplest data formats ever designed.
• JSON does not support comments by design. Crockford removed them because people were using comments to hold parsing directives, which broke interoperability.

FAQ

Does this handle relaxed JSON with comments or trailing commas?

Yes. The formatter auto-corrects single-line and block comments, single-quoted strings, unquoted keys, and trailing commas. Strict JSON input works too — the output is always RFC-8259 compliant.

Can I minify JSON instead of pretty-printing it?

Use the 'minify' indent option to collapse all whitespace and output the smallest valid JSON. Other indents (2-space, 4-space, tab) pretty-print.

Does the JSON formatter sort object keys?

Toggle 'Sort keys' to alphabetize keys recursively through nested objects. Array order is always preserved — arrays are order-sensitive in JSON.