Clean filenames can collide.
Preview the whole batch.
Turn messy names into a consistent set. Catch conflicts, keep your extensions, then download renamed copies together.
| # | ORIGINAL | PROPOSED / CLICK TO INSPECT | CHECK |
|---|
No files match this view.
Inside one rename
An override replaces every recipe step, including numbering. It is checked with the rest of the batch.
Choose or drop up to 500 files, 50 MiB total. Files stay in your browser. ZIP contains copies; originals stay unchanged. Paste mode exports a plan.
Why four files collide
The demo includes both Final Report.pdf and final_report.pdf. Tidying turns both into final-report.pdf. Another pair does the same. Numbering gives every row its own destination.
CON.txt is reserved on Windows, even with an extension. A prefix or sequence resolves it. Click any proposed name to inspect its recipe or edit just that file.
Extension means the final dot suffix: archive.tar.gz keeps .gz. A single leading dot, as in .env, is part of the name.
Checks & sources
Names are compared without letter case and after Unicode NFC normalization. Checks cover common Windows reserved names, invalid characters, trailing dots/spaces and a conservative 255-unit or 255-byte name limit. Folder paths and individual cloud-service rules are outside this check.
Microsoft: filename rulesMDN: local files in your browser
Rules reviewed 18 October 2026. Example filenames are invented. CSV formula-like cells are prefixed with an apostrophe for spreadsheet safety.