About Safe Filename Generator

Strip accents + unsafe chars → filesystem-safe filename. Part of the DevTools Surf developer suite. Browse more tools in the Text / String collection.

Use Cases

• Backend developers sanitizing user-uploaded filenames before storage
• CMS developers generating URL-safe slugs from article titles
• DevOps engineers normalizing build artifact names in CI pipelines
• Content managers converting Unicode titles into safe download filenames

Tips

• Paste any string with accents or special characters to get a safe filename
• The output strips diacritics and replaces spaces with hyphens or underscores
• Use it before programmatically saving user-uploaded file names

Fun Facts

• Windows forbids 9 characters in filenames: < > : " / \ | ? * — while Linux only reserves / and the null byte, leading to cross-platform filename headaches.
• The maximum filename length on most filesystems is 255 bytes (ext4, NTFS, APFS), but this is bytes not characters — a single emoji can use up to 4 bytes in UTF-8.
• The FAT32 filesystem, still used on USB drives, limits filenames to 255 UTF-16 code units and is case-insensitive, causing silent collisions on case-sensitive systems.

FAQ

What characters are unsafe?

`/ \ : * ? " < > |` on Windows; `/` on Unix; control characters on every platform. The tool replaces them with a safe character (default `-`).

Does it handle reserved names?

Yes — Windows reserves names like CON, PRN, AUX, NUL, COM1–9, LPT1–9. The tool appends `-file` to make them valid on every platform.

Are diacritics stripped?

Optional. Default transliterates `café` → `cafe`. Toggle off to preserve accents (filesystems support them; some toolchains don't).

How long should filenames be?

Default cap is 255 characters (the filesystem limit on most platforms). Practical cap is ~100 characters for readability and cross-platform cloud storage.