Which characters are removed?

Characters illegal on Windows, macOS, or Linux filesystems, such as slashes, backslashes, question marks, asterisks, colons, pipes, and angle brackets.

Are reserved Windows names handled?

Yes, names like CON, PRN, or COM1 get a safe suffix added automatically.

Can I process multiple filenames at once?

Yes, put one filename per line and each is sanitized independently.

Does it preserve the file extension?

Yes, the extension is lowercased and kept separate from the length limit trimming.

Is my data uploaded to a server?

No. This tool runs entirely in your browser using standard web APIs, so your input never leaves your device and nothing is logged or stored on our servers.

Filename Sanitizer

Clean up filenames for safe cross-OS use.

Support

Works Offline

Privacy First

No Login

No API

Case

Separator

Max length

Strip diacritics

Strip emoji

Filenames (one per line)

Sanitized filenames

My-Report-(Final)-2024-cafe.pdf

Removed characters that are invalid on Windows/macOS/Linux filesystems.

About the Filename Sanitizer

Sanitize filenames or paths so they work safely across Windows, macOS, and Linux: strip illegal characters, reserved device names, diacritics, and emoji, normalize separators and case, and trim to a maximum length.

Examples

Messy filename

My Report (Final)?? café.PDF

Output

my-report-final-cafe.pdf

Keyboard shortcuts

Copy the main outputCtrl / ⌘ + Shift + C
Download the resultCtrl / ⌘ + S
Share this toolCtrl / ⌘ + Shift + S
Reset the inputsAlt + R
Open the tool search paletteCtrl / ⌘ + K

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Frequently asked questions

Version 1.0.0 · Updated 2026-08-11 · Runs entirely in your browser