How to use Filename Sanitizer
Filename Sanitizer reads the files you select, applies the filename rules you choose, and shows each original-to-proposed mapping before you download anything. One file produces a renamed copy. Several files produce a ZIP with CSV and JSON manifests. The selected files stay in the browser while the names are processed.
- Use browse files to select one or more files.
- Choose values for Character policy, Case style, and the other filename rules.
- Check the Original name/path, Proposed name/path, Status, and Notes columns.
- Choose Download renamed copy for one file or Download ZIP + manifest for several files.
What Filename Sanitizer rules change
Cross-platform safe under Character policy replaces \ / : * ? " < > | and control characters. Strict ASCII portable also replaces characters outside letters, digits, periods, underscores, and hyphens. The cleanup removes extra whitespace, repeated separators, repeated periods, and spaces or periods at the start or end.
Unicode normalization can be None, NFC (compose), or NFKC (compatibility compose). Transliterate accented/foreign letters to ASCII converts supported letters to ASCII approximations. Case style can keep the original case, use lowercase or UPPERCASE, or set kebab-case or snake_case. Those last two styles choose their own separator.
bad:name?.txt
bad-name.txtHow extension and length rules work
- Preserve the final extension (uses the compound-extension rule below) keeps the final dot segment. Recognized two-part suffixes such as
.tar.gz,.min.js,.d.ts, and.spec.tsstay together. Turn it off to clean the whole filename as one string. - Max basename length (characters) limits the cleaned basename and preserved extension together. A long extension leaves less room for the basename. If it leaves too little, the tool keeps a one-character basename.
- Transliterate accented/foreign letters to ASCII removes combining accents and converts mapped characters where supported. Other characters follow Character policy.
- Separator for unsafe characters can be a hyphen, underscore, or no separator. Kebab-case and snake_case set their own separator.
- Reserved base names such as
CON,PRN,AUX,NUL,COM0throughCOM9, andLPT0throughLPT9receive an underscore. - When cleaned paths collide, Collision suffix policy adds Parentheses: name (2).ext, Dash: name-2.ext, or Underscore: name_2.ext. The mapping table labels the affected row
Collision resolved.
Where filename cleanup helps
Clean a batch of source files before adding them to an archive, then review the proposed path changes in the table. Names with spaces, punctuation, or accented letters can be converted to the style required by a delivery folder.
For a destination that rejects reserved device names, fix those names before downloading the ZIP. Manifest CSV and Manifest JSON give you a record of each original path, sanitized path, status, notes, and file size.
When to use a related clean-up tool
Use File Management Clean Tools for a cleanup job that includes more than filename rules. Choose Metadata Remover to inspect or remove embedded fields from image, PDF, audio, or Office files while keeping their visible content intact.
Filename Sanitizer leaves file content, metadata, and originals unchanged. It reads selected files and builds downloads in the browser; the code makes no request that sends file contents to a server. A folder-relative path is shown in the mapping, and its folder segments are sanitized too. The picker has no visible folder control.
Frequently asked questions
Does a filename sanitizer rename original files?
No. It uses each selected file to create a renamed download. The original file on your device stays unchanged.
How does it clean unsafe filename characters?
It replaces unsafe characters and control characters according to Character policy, then applies the selected separator and case rules. It also cleans whitespace, repeated separators, and leading or trailing spaces and periods.
Can it preserve a compound extension such as .tar.gz?
Yes. With Preserve the final extension selected, recognized suffixes such as .tar.gz stay together. Other names use the final dot segment.
What happens when sanitized filenames collide?
The later matching path receives a numbered suffix using the selected Collision suffix policy. The mapping table labels it Collision resolved.
Does the filename sanitizer upload files?
No. The script reads files, creates renamed copies or a ZIP, and exports manifests in the browser. It does not send file contents to a server.