iTunes 10? Don’t Worry
iTunes 10 automatically ignores duplicate tracks. For instance, if you have Light by KMFDM in your library, you will not be able to copy it in again. If you try, iTunes will simply detect the file that’s already yours and play it, without adding an extra to your library.
iTunes 9 and Below
Perhaps you have iTunes 9 and below. Or maybe you had duplicates in iTunes 10 that transferred over from previous versions. Since iTunes may have kept your library intact, those duplicates are still there and you want to get rid of them.
1) Launch iTunes.
2) Hold Alt or Option (Mac) or Shift on Windows. Go to File > Display Exact Duplicates (this item will only show up if you are holding the option or shift keys) It’s important that you go with Display Exact Duplicates, as Apple explains that simply choosing Display Duplicates only goes by track name and artist, meaning if you have a Live version of a particular song and the studio version, it may mistake them for the same song. Choosing Exact Duplicates eliminates this problem.
3) Now you have all your duplicates displayed. Should you go in there and delete each one individually? Nope. We followed Apple’s guide for this. Here’s what they suggest.
4) Earlier versions of iTunes will let you sort by Date Added. Simply click on “Date Added” at the top of your music library (next to Artist and Album). iTunes will sort the songs according to when you originally imported them. This makes it very easy to delete the duplicates by simply highlighting the older copies of the songs (Shift click to highlight multiple). Make sure you aren’t deleting both copies of a particular song before you proceed. If you can’t sort by date, it seems you will have to delete manually. Still, iTunes 10 shouldn’t allow for duplicates in the first place.
5) Go to Edit > Delete.