How to Batch Rename Files on Mac

Step by step

1. 10 sec

   Select every file you want renamed

   Open the folder in the Finder and select the files. Click the first, then Shift-click the last for a contiguous run, or Command-click to pick scattered items. Command + A takes everything in the folder. The rename applies only to what is highlighted.

   Note: Sort the window the way you want the files numbered before you start. The Finder numbers them in the order the window is currently showing.
2. 5 sec

   Open the Rename sheet

   Right-click any of the selected files and choose Rename, which reads Rename 12 Items when twelve are selected. File > Rename Items in the menu bar does the same thing. A sheet drops down with one popup menu at the top offering Replace Text, Add Text, and Format.

   Note: There is no default keystroke for this sheet. System Settings > Keyboard > Keyboard Shortcuts > App Shortcuts will attach a key to the menu item if you want one.
3. 20 sec

   Replace or add text across the batch

   Choose Replace Text to swap one string for another in every selected name, and leave the Replace With field empty to delete that string outright. Choose Add Text to append or prepend a string, with the Where popup set to either before name or after name.

   Note: Replace Text matches anywhere in the name, the file extension included. Aim carefully or you will rename .jpeg into something no application recognizes.
4. 30 sec

   Number the files with Format

   Choose Format, then set the Name Format popup to Name and Index, Name and Counter, or Name and Date. Type your base name into the Custom Format field, set Where to before name or after name, and set Start numbers at to whatever value you want.

   Note: Index counts up in plain numbers. Counter pads the number with leading zeros, which is what you want if the files will ever be sorted as text.
5. 1 sec

   Undo the whole batch if it lands wrong

   Press Command + Z immediately after the rename and the Finder restores every original filename in one move. Edit > Undo Rename in the menu bar does the same. Do this before you click into another window or start any other file operation.

   Note: Do not rely on stacking these. Once you have renamed twice and clicked elsewhere, assume the earlier names are gone and duplicate the folder first.
6. 20 sec

   Know what Quick Actions actually does

   Quick Actions is a separate submenu sitting in the same right-click menu. It holds Rotate Left, Markup, Create PDF, and Convert Image, plus anything you build in Automator or the Shortcuts app. It transforms files. It does not rename them.

   Note: Customize, at the bottom of that submenu, opens the extension settings where you pick which Quick Actions appear and which stay out of the way.