Apps & Tools

Bulk Renamer

A free, open-source native desktop app. Pick a folder, build a rename pattern, preview every result, then apply, nothing touches disk until you confirm.

Download

🍎 macOS Apple Silicon & Intel 🪟 Windows 64-bit installer 🐧 Linux .deb / AppImage

🔓 Fully open-source, view the code on GitHub.

Why a Desktop App

Batch-renaming a folder of files needs real filesystem access, reading a directory listing and calling the OS's rename operation on every file, which a sandboxed browser tab can't do. Every rename batch is validated in full before a single file is touched: it refuses to proceed if two files would end up with the same new name, or if a destination name already exists on disk.

Knowledge Base

What It Actually Does

Pick a folder, and every file in it (not subfolders) loads into a preview list. Configure a rename pattern, find/replace, an added prefix or suffix, sequential numbering, case conversion, or an extension change, and the preview table updates live showing exactly what every file's new name will be, before anything happens on disk.

The Safety Model

Two checks run before any file is renamed: no two files may end up with the same new name, and no destination name may already exist on disk (a same-file case-only rename is allowed). If either check fails, nothing is renamed and the conflicting rows are highlighted so you can fix the pattern. A single "Undo Last Rename" button reverses the most recent successful batch, as an immediate safety net. It's in-memory only and won't survive closing the app.

Pattern Options

Find & replace (plain text or regex), prefix/suffix, sequential numbering with configurable start number and zero-padding, case conversion (lowercase, UPPERCASE, Title Case), and an optional extension change, combine as many as you need in one pass.

FAQ

Q: Is this actually free?
A: Yes, free and open-source under the MIT license. No account, no trial, no watermark.

Q: Can it undo a rename if I make a mistake?
A: Yes, for the most recent batch. An Undo button reverses the last rename it applied. This is an in-memory safety net for catching an immediate mistake, not a permanent history, so it won't help after closing the app.

Q: Will I get a security warning when I open it?
A: Possibly, until code-signing is set up for this project, unsigned apps trigger a standard OS warning on first launch (Gatekeeper on macOS, SmartScreen on Windows). The app itself is unaffected. You can review the source on GitHub before running it if you'd like to verify that yourself.