Bulk File Renamer
Rename several files at once: add sequence numbers, find and replace text (regex supported), change case, or add a prefix or suffix. A browser cannot rename your original files, so the renamed copies are bundled into a ZIP for download. To inspect or extract the archive, use the ZIP Maker & Extractor.
🔒 Runs in your browser · Your data is never sent to a server
Drag and drop files here, or pick several with the button. Each pick adds to the list.
Preview of the new names
Add files to see the names before and after here.
| Before | After | Status |
|---|
How to use
- Drop the files you want to rename into the box.
- Choose the replace, case, prefix and suffix, numbering, and extension options.
- Check the new names and statuses (duplicates, empty names) in the preview table.
- Enter a ZIP file name and press "Save as ZIP".
Notes
- A browser cannot rename your original files directly. This tool bundles copies under the new names into a ZIP; extract it to get the renamed files. Your originals are left untouched.
- Options are applied in this order: replace, case change, numbering, prefix and suffix, then the extension. Replace and case change affect only the part before the extension, which has its own setting.
- Saving is blocked when a new name matches another file (case is ignored) or is empty. Characters that are not allowed, such as / \ : * ? " < > |, are replaced with _ so a name can never act as a folder path.
- Numbers are assigned in the chosen order, from the start value by the step. Up to 10 digits, 5,000 files at a time, and 100 MB in total for the ZIP.
- "Save as ZIP" stores files without compression and puts everything at the top level of the ZIP; folder structure is not kept.
Glossary
Zero padding
Filling a number with leading zeros to a fixed width, like 001, 002, 003. With equal widths, sorting by name also sorts by number, so 10 does not land before 2.
Natural order
A sort that compares digits as numbers, so file10 comes after file2. A plain text sort would put file10 before file2.
Regular expression
A notation for describing text patterns. Parts in parentheses can be reused in the replacement as $1, $2, and so on.
FAQ
Can it rename the original files themselves?
No. For security reasons a browser cannot rewrite the files you pick, so the tool saves copies under the new names in a ZIP. Extract it to get the renamed files; your originals stay as they are.
How do I number files as 001, 002, 003?
Turn on "Add sequence numbers" and set digits to 3. You can change the start value and step, and "Number position" lets you put the number before or after the name, or replace the name with it. Digits go up to 10.
What happens if two new names are the same?
Those rows are flagged in the preview and saving is blocked until they are resolved. Names are compared ignoring case, so clashes that Windows or macOS would treat as the same file are caught too. Add numbering or change the pattern to tell them apart.
What if a name contains characters that are not allowed?
/ \ : * ? " < > | and control characters become _, and trailing dots or spaces are removed. Rows that needed such changes are marked in the preview. Replacing text with something like ../ cannot move a file into another folder.
Can I reuse part of the match in a regex replacement?
Turn on "Use regular expression" and refer to parenthesized groups as $1, $2 in the replacement. For example, replacing IMG_(\d+) with photo-$1 turns IMG_001 into photo-001. Only the part before the extension is matched.
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