Enter a starting number for the file series in the Start numbers at field.Enter a common name for your files in the Custom Format field.

We're going to use Name and Index, but you can optionally select Name and Counter or Name and Date.

In the next dropdown, select a Name format.

Select Format from the first dropdown menu in the Rename Finder Items panel.Alternatively, right-click (or Ctrl-click) one of the selected files in the Finder window. Click the Action button in the Finder toolbar.Drag a selection box over the files with your mouse or hold the Shift key and click them one by one.Open a Finder window and locate the files you want to rename.In our example we're going to be batch renaming some photos. To rename several files of the same kind on your Mac at once, follow the steps below. Since OS X Yosemite however, Apple has integrated several useful batch renaming capabilities directly into Finder. In early versions of Mac OS, users looking for a way to quickly rename multiple files simultaneously (commonly referred to as batch renaming) had to use the command line or download and install a third-party tool dedicated to the task.

Mass file renaming tool for mac