ID3 Tag Basics


Oct 15, 2008

ID3 tags have caused people problems for years and the first jump from CDs/folder based MP3 players etc to something that sorts by ID3 tag leave a lot of people in shock when the player says "unknown track" for all their music.

ID3 tags are basically information tags inside the MP3 file that tell the player all sorts of things. It can be as simple as artist and album or as complex as having 20 high resolution images of the cover and booklet inside the same MP3 file. Read on for a roundup of this feature and a how to on tagging your files.

MetadataTechnically ID3 is MP3 specific and the correct term to use for general tags in audio files is metadata. FLAC and Vorbis use vorbis comments for tags, WMA uses a feature in the ASF container and so on. Using ID3 with these formats won't work and might cause problems. This article will focus on ID3 tags for MP3 files. Some techniques might bee the same, others might be different with other formats.

ID3 versionsThere are several ID3 versions but the most important ones to know the difference between is ID3v1 and ID3v2. ID3v1 (aka IDentify MP3 version 1) is rather limited with a specific number of tags and character limits. This is mostly used by old players. ID3v2 and above support ID3 sizes up to 256MB with no character limit so you can basically save all the Harry Potter books in the comment field of an MP3 field if you like. The actual specs of the versions are not important because players will have their own limits anyways, but if you have an old player and have trouble with ID3 files do a google search and see if it supports ID3v2.

TagsThe ID3 tags are the information fields that you see in ID3 editors and also what players allow you to browse music by. Common tags used on MP3 players include album, artist, title, year and genre. There are several more and you can make your own if you want, however you won't make the player sort by them. Missing information in the ID3 tags is what makes the player list songs as unknown, as the track might not have any title or album information even if the file name does.

The basic artist tag is for the song artist - not surprisingly. There are more advanced tags that cover composer, album artist and so on but those aren't read by most players. If the player show a different artist than the artist tag however, you probably have a player that reads album artist instead. A common problem with the artist tag is that you have songs form the same artist where the artist name is written slightly different, causing two entries in the artist list on the player. One file might say "Pink Floyd", another "pink floyd", a third "Pink floyd" and a fourth might say "Pink Floyd and Ziggy Stardust". These will appear as four different artists. To avoid this you can open all files from one artist in a tag editor and edit the artist tag of all of them at the same time (by selecting several).

Album is also rather self explanatory and have it's own set of common problems. One of the most annoying ones are songs that are tagged with re-release albums rather than the original album. For instance. Pink Floyd's "Another Brick in the Wall Part 1" might be tagged with "Best of 1979" rather than "The Wall", making it a completely separate album entry. It would also affect the album art and you might get an ugly cover from a best of CD instead of the real thing. It might also be tagged "The Wall CD1" which would make it a separate entry from CD2 which would cause problems if you wanted to listen to the entire album at once, as some players stop after playing all files in the album entry selected.

Title is easily confused with file name. Title is the name of the song and is what the player will display if ID3 based. A file you get from shady places might be name 021-smoke.on.the.water-320kbps.MP3. Renaming this to Smoke on the Water.mp3 would make it display properly on the computer, but if you transferred it to the player it might display as 021-smoke.on.the.water-320kbps again. That's because the title field isn't filled in properly and in this instance the title field is 021-smoke.on.the.water-320kbps. The same thing can of course work in reverse, that a file named 021-smoke.on.the.water-320kbps.MP3 has the title field filled in correctly and it will display correctly. The point is to check the title field to make sure it's filled in correctly, as ID3 based players listing songs by title won't display them based on file names as many think.

This might be the least used ID3 tag and it simply says what year the track was released. Again this might be screwed up by "best of" collections as they might tag the file with the release year of the best of CD not the original year. Some players use this tag more than others, for instance Sony players that have a time machine shuffle that picks a random year and plays a song from it.

Genre is also rather self explanatory but just like the other it has some annoyances. A lot of music fit into more than one genre and which one is right is subjective. You basically have to pick one and if you manually write "rock and metal" or something of the sort that will list "rock and metal" as a separate genre and not list the file in both rock and metal. Sansa players (Clip and Fuze) use the genre tag for something a little different; podcasts and audio books. By tagging the file as audio book or podcast the player sorts the files into their own directories with special playback controls made for such materials.

Commenter Shur also mentioned another tag some players use that I'd forgotten: ratings. Some players allow you to rate songs and also sort files based on rating. Software on the computer side might also be used to make playlists and such based on rating.

Album ArtAlbum art is a feature used by most new players that have a color screen and is a picture file embedded in the MP3 file that allow for displaying the album cover (or other pictures) on the player. Album art is often very restricted depending on what player you use. Sansa players won't read the album art if its over a specific resolution or file size and when the numbers are low (say 200x200 pixels max) that causes problems since album art is often 500x500. Another problem is file format; ID3 don't convert the picture files in any way so if you embed a .pgn file the player will have to be able to read png to display it. JPEG is mostly used and most compatible, so if you have album art that won't display and you can't figure out why - check file format, resolution and file size. It's also worth mentioning that players will normally only show one picture per file, while ID3 supports many. I've seen many instances where album art won't show either because there's a blank file in the first position of the album art or that the player won't read any picture if there's more than one.

SoftwareThere is a lot of software capable of tagging files and music management software like Media Monkey is also very capable of doing so. There is however one piece of standalone software that is used the most, MP3tag. It's Windows only so if you're using Linux or Mac you'll have to find other alternatives. MP3 tag also supports other formats that don't use ID3 - like FLAC and Vorbis - so this tutorial is useful also if you don't use MP3 files.

Getting MP3tag
MP3tag is available for download for free (if you use this a lot, donating is appropriate) from When you download and install the application, you will be prompted for various shortcuts to install and I suggest adding the one for right clicking in explorer (context menu) and selecting MP3tag as that one is very useful.

Using MP3tag
Here we have a perfect example of an untagged file. It doesn't look pretty and it's hard to navigate your music if all files are like this. Opening this file in MP3tag shows that it's missing all the crucial tags including artist, album and title. There's also no album art as you can see from the blank box in the bottom left corner.
There are two ways to tag from this point, either manually or semi-automatically. If you tage manually, you just select the file(s), change the tag fields on the left, add album art by right clicking -> add cover and click the floppy disk save icon. Be aware that if you don't click the save icon and simply deselect it won't save the changes and you'll have to do it all over again.

The semi-automatic way of doing it is to use an external database to find the info for the files. This is preferred, especially is you have a whole album as typing in titles one by one is a drag. To do this, select the files, click the "tag sources" menu on top and select a source - i usually prefer This will prompt you with a search box. If album or artist field is filled in on the files already, the default search will be for this. In this case, it has nothing to go on so you have to type in what to search for manually. If you don't know what album the track came from that might be a problem, if so a google search might be helpful. In this case the album title is in the file name so it's easy to find. Once you know the album name, type it in.

After searching you get a list of possible albums, normally a long list if it's a popular album since there are many different editions. Pick one that fits and select next, and you'll get to the album information screen.

If you chose the right album in the list, the album information screen should be full of information that fits your album. If you tag just one file like I did in the example, you sometimes have to use the "move up"/"move down" buttons to position the track you have (right bottom list) so it corresponds with the database's list (left bottom list). Otherwise it'll overwrite your file with the tag info for another song on the same album. In my case the single file was track number 1, so it already matched up. Also note that sometimes our own files aren't in the correct order due to file name issues (lacking track number for instance) and then you have to match them up manually. Basically just check that the two lists match before you click OK. On rare occasions there aren't any info on the albums at all (lacking album art, track list etc). if so, search again and pick another one in the list. If none matches, try another database, and if all fails you have to find the info yourself and do it manually.

Once all is done on the information screen, click OK. It will tag your files and promt you with a message when it's finished. It doesn't take long at once it's done your files will be ready to go. I have at times had single files in an album failed tagging, normally this is just a bug (or maybe the file is in use) and just try again and see if it works. If all goes well, the tag fields will be filled in and the album art will be in place.

Lastly it might be a good idea to change the file name so it's not so messy. MP3tag allows for making tags out of filenames and vice versa. This can also be used to tag the file in the first place (if the file name has all the info) but generally it's faster to just do a database search. It is however very useful for batch changing file names. Select the files, right click and select Convert -> Tag - Filename. A box will open prompting you to enter format string. This is the layout of the file name, and you can use the arrow button on the far right to select these strings from a drop down menu. For instance, if I want the track number first, a dash for separation, the artist name, another dash and the title, I'd select track form the drop down menu, type in a dash, select artist from the dropdown menu, type in another dash and finally select title from the dropdown menu. After a while you'll learn the format strings and can type them in manually but it's just as easy to just select them from the list. You'll see a preview of how the filename will look so when you're satisfied just press ok and it'll change the filenames.

That's it, you're done, and all that's left is to transfer the files to the player. Be aware that some players that save ID3 info in a database on the player won't notice small changes in the files such as ID3 tags. What that means is that if you have a untagged file on the player, make changes and transfer the file (overwriting the old one) it might not show the new ID3 info. If this happens, delete the file on the player, disconnect the player, reconnect and transfer the new file. Enjoy the bliss that comes with ID3 perfection :)