Bulk File Renamer
Rename files in one ZIP
Choose up to 200 files totaling 100 MB. Preview the names, then download the renamed files in a ZIP. Processing stays in your browser; your original files stay unchanged.
Choose files to preview their new names.
About Bulk File Renamer
Bulk File Renamer creates a ZIP of copies with revised filenames. Choose files, apply a prefix, suffix, literal text replacement, or sequential numbering, and inspect the original and proposed names before downloading. The naming rules operate on the part before the final extension, so you can organize mixed file types without changing their extensions. Processing happens in your browser. The tool does not rename files in their original folder or write changes to your filesystem; you receive a new archive containing the selected file contents under the previewed names.
How to Use Bulk File Renamer
Select the files for one batch
Choose up to 200 files totaling 100 MB or less. The tool works with filenames and file bytes, so the selection can include different file types. Check that the chosen files are the ones you want to include in the ZIP. Use Clear files if you need to discard the selection and start again.
Enter the naming rules
Add a Prefix before each filename stem or a Suffix after it. Find literal text replaces every matching occurrence in that stem and is case-sensitive. Leave Replace with empty to remove the matched text. Enable Add numbering and choose a whole starting number if you want a sequence appended after the suffix.
Inspect every proposed name
Compare the original and new names in the preview. Numbering follows the chosen file order and appears as -1, -2, and so on, using your starting value. Unsafe characters, reserved names, long names, and collisions can cause additional filename adjustments. Read the preview after each rule change so you know which names the ZIP will contain.
Download the renamed ZIP
Click Download renamed ZIP once the names are correct. Extract the archive to use the renamed copies. Keep or remove the original files yourself according to your workflow. The ZIP is a new download; completing it does not replace the original folder contents or apply the displayed names to files already on your device.
Common Use Cases
Add project context to a file collection
Give attachments a shared project prefix or add a revision suffix before handing them over. A mixed collection can retain its original JPG, PDF, and document extensions while gaining a common naming pattern. If you also need to resize or convert a set of images, use Batch Image Processor for that separate preparation step, then rename the files you intend to share.
Remove repeated text from exported filenames
Use literal find and replace to remove an unwanted export marker or replace an old project name. Replacement applies only to matching text in the filename stem and leaves document or image contents untouched. If your files are photographs and you also need to remove embedded camera metadata, use EXIF Remover as a separate step.
Technical Specifications
| Input Formats | Files of any type |
|---|---|
| Output Formats | ZIP |
| File Size Limit | No strict limit (dependent on device memory) |
| Processing Engine | 100% Client-side (Runs locally in your browser) |
| Data Retention | Files never leave your device |
| Batch Processing | Yes (multiple files supported) |
Tips for Best Results
Read a compound filename by its final extension. For report.final.pdf, the editable stem is report.final and the extension is .pdf. A dotfile without another extension is treated as a whole stem.
Replacement runs before the prefix and suffix are added. Numbering is added after the suffix, before the extension. For example, adding prefix client- and numbering from 1 to photo.jpg produces client-photo-1.jpg.
The size limit applies to the entire selection, not to an individual file. ZIP creation needs browser memory for the selected bytes and archive, so split the work into smaller batches when your device struggles.
Filename fields allow up to 200 characters each. Output names are limited to 240 UTF-8 bytes, so non-ASCII names may reach the byte limit with fewer visible characters. Always use the preview as the final name reference.
Frequently Asked Questions
Will this rename the files in my original folder?
No. The browser creates a ZIP containing copies under their new names. Your selected source files keep their original names and locations. Extract the download to obtain the renamed copies, then decide yourself whether they should replace any existing files.
Can I use regular expressions or ignore letter case?
Find and replace uses literal, case-sensitive text. It replaces every exact match before the final extension. It has no regular expression syntax or ignore-case option. To change a value written in several different ways, review the source names and plan separate batches when necessary.
Does the suffix go after the file extension?
No. Prefix and suffix wrap the filename stem, and numbering follows the suffix. The final extension remains at the end with its original letter case. For example, a suffix of -review changes invoice.PDF to invoice-review.PDF before any numbering or collision adjustment.
What happens when two output names would be identical?
The planner gives later collisions a parenthesized number such as (2) or (3) before the extension. Collision checks also account for case differences and normalized names. Both files remain in the ZIP under distinct names, and the preview shows the adjusted result.
Why did a character turn into an underscore?
Characters unsafe in common filenames, including path separators, are replaced with underscores. Reserved names receive an underscore prefix, trailing dots and spaces are removed, and overlong names are shortened. These adjustments keep archive entry names usable, so check the preview when exact spelling matters.
Does renaming convert or compress the file contents?
Renaming does not decode or convert the selected files. Their bytes are copied into the ZIP, and extensions are preserved rather than changed to represent another format. The archive groups the copies for download; it does not promise a smaller total size.
Can I select a folder and preserve its subfolders?
The current control selects files and produces one set of renamed archive entries. It does not offer folder traversal or a control for preserving a directory tree. Select the files you need and inspect their displayed order before relying on sequential numbering.