We often find ourselves with a folder full of items whose names need to be adjusted. For example, adding an identifying name to photos, along with a sequential number. Or changing the names of files for a website to lower case and replacing spaces with underscores. Most recently, we had hundreds of image files from a digital camera that all had an odd file name extension and so wouldn’t open (although we knew they were just JPEGs). The best file-renaming solution we’ve found is Dare to be Creative’s Renamer ($19.99).
Renamer makes it easy to rename a large number of files. You just drag files or folders into its window, then configure your changes. As you define your intended changes, Renamer previews what each new file name will look like. When the file names appear the way you want them, you can apply the changes.
It has plenty of options: you can remove or replace words or characters, insert text anywhere in the file name, add sequential numbers at either end of a file name, convert to UPPERCASE, lowercase or Word Caps. It’s powerful enough to process regular expressions (calculations and wildcards), and can rename files recursively through nested folders. You can also use it in the Finder as a contextual menu item — just Control-click or right-click a file or folder.
You can even save renaming tasks for future use, or chain them together for complex renaming tasks.
We use Renamer regularly.