Bulk File Renamer
About Bulk File Renamer
Pick a folder and rename every file directly inside it with one pattern — add text, find & replace, number them in sequence, or stamp each photo with its own capture date. A live preview shows the exact result before anything is touched.
Renaming a handful of files by hand is easy; renaming two hundred of them the same way is not, and most "online" renamers either want you to upload the files first or are really an ad for a desktop app. This one works entirely against a folder you pick on your own device using the File System Access API — nothing is uploaded, and nothing is copied anywhere. It reads each file, writes it back under its new name, and removes the old name, right there in the folder you picked.
The preview updates as you type, so a mistake in a find/replace pattern or an empty prefix is obvious before you commit to anything. Two files that would end up with the same new name are automatically kept apart with a "(2)", "(3)", … suffix, and a file whose name the pattern doesn't actually touch is never disturbed — it keeps its exact name even if something else you're renaming would otherwise collide with it.
This only renames files sitting directly inside the folder you pick — it does not reach into subfolders. Renaming genuinely changes files on your disk and cannot be undone by this tool, which is exactly why the preview is not a separate confirmation screen you click past: it is the whole setup screen, updating live, so you see precisely what you are about to do.
What you can use it for
- Add a consistent prefix or suffix to every file in a folder
- Find and replace a piece of text across many filenames at once
- Number a batch of files in sequence, like photo-001.jpg, photo-002.jpg, …
- Rename a folder of photos using each photo's actual capture date instead of its camera-assigned filename
How it works, step by step
- 1
Pick a folder
Choose the folder whose files you want to rename.
- 2
Choose a pattern
Add text, find & replace, number in sequence, or use each photo's capture date.
- 3
Check the preview
Every file's exact new name is shown live — uncheck any file to leave it alone.
- 4
Apply
Files are renamed in place inside the folder you picked.
Frequently asked questions
Are my files uploaded anywhere?
No. Everything happens on your device using the File System Access API — files are read from and renamed inside the folder you pick, and never leave it.
Can I undo a rename?
Not with this tool — renaming happens immediately once you click apply, and there's no built-in undo. That's exactly why the preview is always live and visible before you apply anything, rather than a confirmation dialog you might click through without reading.
What if two files would end up with the same new name?
The second one automatically gets a "(2)" appended before its extension, and so on — nothing ever silently overwrites another file.
Does it rename files in subfolders too?
No — only files directly inside the folder you pick. Subfolders are left completely alone.
Does this work in Safari or Firefox?
Not yet. It needs the File System Access API to read and rename files on your disk, which currently only Chrome, Edge and other Chromium browsers support.