If you've got a hefty iTunes library that's been transferred over from Mac to Mac or PC to PC, odds are you've run into issues with duplicate songs. It happens from time to time and as your library grows, so do the problems that come with it. For the most part, ridding your library of duplicate tracks is a pretty painless process.
It's important to note that sometimes iTunes can confuse different mixes and slight variations that come on different albums. So make sure what you're deleting is actually a duplicate and not a remix or version from a different album. That's why we recommend using the exact duplicate option explained in the steps below.
If you're still having issues or have a massive library that requires a more powerful and less time consuming option, apps like TuneUp can not only automatically clean up duplicate tracks, but also replace missing cover art and fix album titles. If you're looking for something more slimmed down with a lighter price tag, Song deDuper is a cheaper option and available in the Mac App Store. Song deDuper allows you to narrow using several criteria and can clean out your library without the need for you to manually delete duplicates. It's not as powerful as suites like TuneUp but it does what it says it will, and does it well.
If you've used other software to remove duplicate tracks from your library, let us know what you used and how well it worked in the comments. Especially you Windows users out there!