Filename Sanitizer
Clean up a filename to remove characters that cause problems.
A safe, tidy filename
Some characters in a filename cause trouble — they are forbidden on certain systems, break in URLs, or confuse scripts. This cleans a filename by removing or replacing problematic characters, producing a safe, portable name.
Enter a filename to sanitise it.
Why filenames need cleaning
Filenames run into real compatibility problems because different systems have different rules about what characters are allowed. Certain characters are outright forbidden on some operating systems, spaces and special characters cause issues in web addresses and command-line scripts, and characters from other alphabets or emoji can behave unpredictably when files move between systems. A file with a problematic name might refuse to save, fail to upload, or break a script that processes it. Sanitising produces a name that works everywhere — typically sticking to plain letters, numbers, hyphens and underscores, avoiding spaces and special characters. This matters most when files are shared across systems, uploaded to the web, or handled by automated processes, where a clean, predictable name prevents a whole class of frustrating errors. It is a small step that saves real trouble when files travel beyond the machine they were created on.
Questions & answers
Why do some filenames cause problems?
Because systems differ on allowed characters — some are forbidden on certain operating systems, and spaces or special characters break in URLs and scripts.
What makes a safe filename?
Sticking to plain letters, numbers, hyphens and underscores, avoiding spaces and special characters, so it works across systems and the web.
Is anything uploaded?
No. The sanitising happens in your browser.