Bulk Renamer vs Bulker

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.

Bulker has no write-up on Specifiction yet; its figures are above.