With the large iTunes libraries that most users have, it can be easy to inadvertently end up with duplicate copies of the same song unnecessarily taking up space on your hard drive. But in a library of thousands or tens of thousands of songs, it can be hard to find the duplicates--especially when you might have multiple versions of a song that you want to keep (say one from the CD, another from a live concert). Luckily, there's a built-in feature that lets you easily identify iTunes duplicate.
View & Delete iTunes Duplicates
You can have iTunes sort itself for all songs that have the same song name and artist name. To dot his in iTunes 11 or higher, go to the View menu and click Show Duplicate Items. In iTunes 10 or earlier, go to the File menu and click on Display Duplicates. ITunes will create a list of all duplicates songs and display them in the right-hand side of the window. You can then sort them by Name by clicking on the column at the top of the window or Date Addedby clicking that column. This will allow you to see the songs next to each other and determine which duplicate, if any, you want to delete.
In iTunes 11 or higher, to return to the standard view of your music library, choose the View menu and then click Show All Items.
View & Delete Exact Duplicates
The Display Duplicates command can be useful, but it's not always completely accurate. Since it only matches songs based on their name and artist, it often shows songs that are similar but aren't exactly the same. For instance, an artist might record the same song twice at different times in their career. While Display Duplicates will show these songs as being duplicates, they're actually not and you'll probably want to keep both versions.
In this case, you need a more accurate way to view duplicates. ITunes also offers this in the form of Display Exact Duplicates. Access this command in the same way as Display Duplicates, except when you click on the File or View menu, hold down the Shift key on Windows or the Option key on a Mac. When you do this, the option in the menu will become Display Exact Duplicates. Click that.
Now you'll only see songs that have the same song name, artist, and album. Since it's unlikely that more than one song on the same album will have the same name, you can feel more confident that these are true duplicates. As usual, you can sort by Name or Date Added to compare all files.
How This Affects Playlists
It's important to note that if you remove a duplicate file that's in a playlist or similar location, it won't be automatically replaced by the original file. You'll need to add the original file to that location manually.
Learn more about deleting songs in iTunes from this tutorial.
When Not to Delete Exact Duplicates
Some of the files that Display Exact Duplicates shows may not be truly exact. Though they may have the same name, artist, and album, these duplicates may be different kinds of files or saved at different quality settings. For instance, two songs might be in two different formats (say, AAC and FLAC) intentionally, since you want one for high-quality playback and the other for small size to use on an iPod. You can find this information about the files by getting more info about them. With that, you can decide whether you want to keep both copies or remove one.
Go Back to Regular View
When you're done looking at the iTunes duplicates, click the Display All button at the bottom of the window to return to your standard iTunes library view.
Got a tech support question? Ask it in the discussion forums.
Want tips like this delivered to your inbox every week? Subscribe to the free weekly iPhone/iPod email newsletter.