If your music and video library is a mess then an ID3 tag editor lets you restore order to chaos.
ID3 tags are the hidden metadata in multimedia files which include important information such as the name of the track and a copy of the album art. Some CD ripping software such as iTunes automatically downloads this information and adds it to the files as you rip songs from disc. But depending on the source of your music, your metadata might be a mess.
Rather than using iTunes to edit track data, tools such as TagScanner and MP3Tag are more powerful when it comes to batch editing – especially if you don't have the original CD at hand.
MP3Tag's interface is more user-friendly than TagScanner, with simple and clean menus. It's a good choice if you only need to make minor tweaks such as using a consistent album or artist name across a bunch of files. If you're starting from scratch you can search several online databases for album details, but TagScanner offers a wider range, including more non-English databases.
TagScanner's interface is a bit more daunting although, once you know your way around, it's just as useful for tweaking metadata or starting from scratch. It has a built-in media player for previewing your files, whereas MP3Tag relies on an external application such as Windows Media Player.
Both applications have lots of advanced features and support regular expressions, although the advanced features are easier to find in TagScanner's tabbed interface. Both can rewrite file names based on ID3 tags and vice versa, and both can also export playlists as M3U, HTML or CSV files.
Both applications are useful but if you only need to clean up a few metadata errors then MP3Tag's basic interface is easier to work with. If you're looking for advanced batch editing features then you might find TagScanner easier to use once you find your way around.