File Renamer by Yoshinya
Renaming files one at a time is slow, and a good naming rule is easy to get wrong by hand. Build the rule once — prefix, date, index — see every new name before you commit, then download the whole batch as a zip.
- Free
- No sign-up
- Processed in your browser
🔒 Your files are not sent to a server. All processing happens in your browser.
① Upload files
Drop files here, or click to choose
② Build the rename rule
Drag tokens into the rule area below to build the file name
Drop tokens here.ext
③ Preview new file names
Add files to see the preview
Add files to enable the download
Guide
How to use the tool
- Drop your files onto the upload area, or click to choose them. They are read in your browser and never uploaded.
- Drag the files into the order you want. That order becomes the numbering order for the index token.
- Drag tokens into the rule area to build the new name: Text, Separator, Date, Time, Index, and Dimensions.
- Check the preview. Every file shows its old name beside its new one, and duplicates are flagged before you download anything.
- Press *Confirm and download*. The renamed files download together as a single zip.
When is it useful?
- Photos straight off a camera or phone all carry names like DSC_0431.JPG that say nothing about what they show.
- Files for a client or a marketplace have to follow a naming convention exactly.
- A folder of scans or receipts needs dating and numbering before it is filed.
- Assets for a website need consistent, predictable names before they are uploaded.
- Someone sent you a batch of files whose names are a mess and you would rather not fix them one at a time.
Privacy and security
Your files are read and renamed entirely inside your browser. Nothing is uploaded to a server, no account is required, and closing or reloading the page discards everything. Because the files never leave your device, the tool can be used with confidential material in workplaces where uploading to an online service is not allowed.
Frequently asked questions
- Are my files uploaded to a server?
- No. The files are read and the zip is built in your browser using your own device. No file or filename is sent anywhere.
- Does it change the original files?
- No. The originals on your disk are left untouched. The tool produces a new zip containing renamed copies.
- How many files can I rename at once?
- There is no fixed limit; the practical ceiling is your browser’s memory. Hundreds of ordinary documents are fine, and very large media files are best done in smaller batches.
- What happens to file extensions?
- They are preserved. A rule is applied to the name only, so report.pdf becomes something like 2026-04-01_report_01.pdf.
- What if two files end up with the same name?
- The preview warns you and *Confirm and download* stays disabled until it is resolved. Adding an Index token gives every file a unique number.
- Can I control the order of the numbering?
- Yes. Drag the files into the order you want before adding an Index token — the list order is the numbering order.