Bulk Rename Utility is a Windows app, and people searching for it on a Mac are usually after the same thing: something with more power than the Finder right-click. The Mac options are real, but they are not one category. They are three, and picking from the wrong one is why people end up with an app that still cannot do the job.
The question that decides it
Before comparing any apps, answer this: where does the correct new name come from?
- If it comes from the old name, edited a bit, you need a pattern renamer. Possibly you need nothing at all beyond Finder.
- If it comes from information stored inside the file, like tags on an audio file, you need a content aware renamer and no amount of pattern power will substitute.
- If it comes from your head, one file at a time, no tool helps and you should just rename them.
Group 1The one you already have
Finder's Rename Items handles find and replace, adding text, and building sequential names. It previews the result, it undoes with Command-Z, and it costs nothing.
The honest advice is to exhaust this before installing anything. A large share of bulk renaming is one find and replace across a folder, and this does that perfectly.
Group 2Pattern renamers
These give you what Finder withholds: multiple rules in sequence, regular expressions, case conversion, character stripping, numbering with control over padding and start point, and usually a preview grid.
They are the right answer for structured messes. Files exported by a system that names things consistently but badly, footage from a camera, a folder that needs a date moved from the end of the name to the front. If your files are all wrong in the same way, this group will fix them fast.
The limit is the same one Finder has, just further away. The input is still the old name.
Group 3Content aware renamers
These open the file and read it. For audio that means the tags: artist, title, album, version, BPM, key. The new name is assembled from those fields, so the old name can be complete nonsense and the result is still correct.
This is the group that fixes a folder where nothing is consistent, which is what most real libraries look like after a few years.
What to check before you pay
A real preview
Old name and new name side by side, for every file, before anything happens. Renaming is not undoable once you have closed the app, so the preview is the safety.
Collision handling
Ask what happens when two files end up with the same name. The answer should be that the duplicate gets numbered, never that one overwrites the other.
Whether it touches the file
A renamer should change the name. For audio, check whether it also rewrites tags, and whether it ever re-encodes the audio itself. Renaming should never cost you quality.
How many files it will take
Some tools slow to a crawl past a few hundred. If your library is in the thousands, that is the number to test with, not fifty.
For an audio library specifically
If the folder is music, you are almost certainly in group three whether you realised it or not. The names came from too many places to have a pattern, and the information you want is already in the tags.
That is what RenameBrooo is built for. It renames thousands of audio files in one pass, reads and repairs the ID3 tags, and can build the filename from artist, title, version, BPM and key. There are presets for speed and custom rules when you want control, every change is previewed side by side first, and the audio itself is left alone.