Batch File Renamer vs Bulk Renamer

Batch File Renamer is a free, open-source web app for preparing new names for multiple files and previewing the results. It processes files locally in the browser, does not upload them and leaves source files unchanged. Ten operations cover find and replace, prefixes and suffixes, case changes, numbering, date and time, regular expressions, cleanup and extension changes. Presets handle numbering, date prefixes, filename cleanup, music files, episode formatting, lowercase conversion and replacing spaces. Users can save reusable operation chains in browser local storage and undo or redo changes across 50 operation states. Validation flags invalid or empty names, reserved Windows device names, trailing spaces or periods, names over 255 characters and duplicate selected outputs. Export creates a ZIP archive containing selected valid files as renamed copies rather than changing originals on disk. Modern browsers support file import; folder picking is best in Chromium-based browsers, and save-picker support varies. The MIT license permits use, modification and distribution subject to its notice. The web plan costs nothing and needs no installation or registration.

Bulk Renamer is a free desktop app for batch-renaming files in a chosen folder, available for Linux, macOS, and Windows. It displays a live preview of each proposed filename before applying the batch. Rename patterns can combine find-and-replace, prefixes or suffixes, sequential numbering, case conversion, and extension changes; find-and-replace accepts plain text or regular expressions. The app loads files from the selected folder but does not include subfolders. Before a batch runs, it checks whether destination names duplicate one another or already exist on disk, and a conflict blocks the operation. Undo reverses the latest successful batch only. That history is kept in memory and does not remain after the app closes. Bulk Renamer is open-source under the MIT license and its free plan costs nothing, with no account required. The maker notes that an unsigned app may trigger standard Gatekeeper or SmartScreen warnings on first launch until code-signing is set up. Infinite Creation describes its free tools as serving people who create, validate, publish, and teach media.