iTunes 11 came with several changes, many of which we detailed in our iTunes 11 Tips feature a couple of weeks ago.
One of the changes made was the loss of a “find all duplicates” feature that was really handy for finding and deleting duplicate files in our rather voluminous iTunes libraries. Luckily, Apple re-included the feature in the latest version of iTunes 11, version 11.0.1
Make sure you have the latest copy of iTunes, of course–head into Software Update and let it do its thing. UPdate iTUnes to the latest version
Once you have iTunes launched, head up to the View menu and choose “Show Duplicate Items.” THe iTunes media window should then update, showing you all the files that are considered duplicates. The list will include all versions of the files that seem to be the same, so be careful you don’t just Select All and Delete.
Which file should you dump? Well, if they’re exact duplicates, it won’t matter. The best way to figure out whether they are, in fact, twinsies, is to use the Information window, which can be brought up with a Command-click on each of the duplicated files, then hitting XCommand-I on your keyboard. CLick over to the Info tab and then use the arrows in the lower left to flip through the info about each file. If you don’t notice any difference in bit rate or encoding, or whatever might change from one file to the next, you have perfect duplicates. Delete either one. IF, however, you see that one file is at a lower encoding rate, or is perhaps a lower-quality recording, get rid of that one.
Via: OS X Daily