Free · no upload · no account
Bulk File Renamer
Rename a whole folder at once with find & replace, sequential numbering or case rules. Every new filename is previewed before you download the renamed set as one ZIP — the files never leave your device.
1 · Pick files
Drop files here
or choose them from your device
Nothing is uploaded: names are read for the preview, bytes are only read when you build the ZIP.
2 · Rename rule
3 · Preview & download
No upload — the ZIP is built in your browser.Pick at least one file to enable the download.
How it works
Drop a folder's worth of files or pick them. Only their names are read at this point.
Find & replace, add numbers, or change the case — one rule set applies to every file in order.
Every row shows old → new plus warnings. When the names are clean, one click builds the ZIP locally.
Built for messy folders
No upload, no account, no storage. The ZIP is assembled with a small built-in ZIP writer.
Illegal characters are stripped or replaced, and empty or colliding names are flagged so nothing gets overwritten.
Rules touch the filename by default; the extension is only changed when you ask for it.
FAQ
Are my files uploaded anywhere?
No. Renaming happens entirely in your browser; file contents are read only at the moment you press download, and the ZIP is created locally.
How are the numbers assigned?
In the order the files appear in the preview, starting at the start index you set, padded to the width you choose (001, 002, …).
What do the warnings mean?
"illegal characters removed" means characters that break file systems were replaced with _. "empty name" and "duplicate name" block the download until you adjust the rule.
Does the ZIP keep the original quality?
Yes — files are stored byte-for-byte, only their entry names change. No re-encoding, no compression loss.