Rename many files

1. 01Choose files or a whole folder, or drag them here.
2. 02Set the rules. The preview shows the old and the new name of every file right away.
3. 03Once the preview reports no problem anymore: “Create renamed ZIP” and save the ZIP. Unpacked, you have the files with the new names.

What the tool cannot do. It does not rename anything on your device. A web page is not allowed to do that, and this tool does not ask for access to your folders either. You get copies with new names. You delete the originals yourself once you are happy with the result.

Order of the rules. 1 New base name, 2 Find and replace, 3 Cut characters, 4 Umlauts and special characters, 5 Spaces, 6 Upper and lower case, 7 Text before and after, 8 Date in front, 9 Number, 10 Extension. What you type in 7 therefore stays exactly as it is: rules 4 to 6 have already run by then.

What counts as an extension. The part after the last dot, if it has at most 10 letters or digits. So “archive.tar.gz” has the extension “.gz”. A dot at the very start (as in “.gitignore”) does not make an extension. Files without an extension are renamed as a whole. A name like “Version 2.5” looks to the tool as if it had the extension “.5”; it then simply stays.

Every new name is checked. Two files must not have the same name, not even if they differ only in upper and lower case: Windows and macOS treat “Photo.JPG” and “photo.jpg” as the same file. A file must not be named like a subfolder next to it either. A name must not be empty, must not contain any of the characters forbidden on Windows (\ / : * ? " < > |), must not be named like a device (CON, PRN, AUX, NUL, COM1 to COM9, LPT1 to LPT9), must not end in a dot or a space and must not be longer than 255 bytes. An umlaut counts as 2 bytes, an emoji usually 4 or more. As long as a row reports a problem, there is no ZIP.

Date and change time. The date in rule 8 is the date of the last change, as your device reports it to the page, in the local time of your device. It is not necessarily the date a photo was taken: if a photo was copied or edited, it can differ. In the ZIP, every file keeps its original change time (accurate to 2 seconds, as the ZIP format provides). For a file saved on its own, your browser instead sets the time of saving.

The ZIP. The files are stored unpacked and unchanged in the ZIP, byte for byte like the original. For that, the tool calculates a checksum (CRC-32) for every file. Files from a folder keep their subfolder. Only the file itself is renamed, not the folder. To unpack, the file manager of Windows, macOS or your phone is enough.

Limits. At most 5,000 files and 2 GB together. From 500 MB on, checking takes noticeably long, and your device needs room for the ZIP and the unpacked copies. With several thousand files, the preview reacts a bit slower while you type. If a file on your device changes after you loaded it here, the browser can no longer read it: the row is then marked red. Take the file out of the list and load it again. Find and replace looks for the text literally, there are no search patterns (regular expressions).