Guides
Guides
Everything here comes from fixing real files: my own library, the practice file on this site, and the ones people email about. Where a guide quotes a number, it's one I measured.
- What's actually inside an MP3 tag: ID3v1, ID3v2.3 and ID3v2.4 in hex
The bytes of a real tag, front and back of the file, with each part explained. Why 2.3 is still the default.
- How to see what's in an MP3's tag on a Mac, Windows or Linux without installing anything
Finder, Windows Properties, VLC, ffprobe and Spotlight's mdls, with real output, plus the quirk each one has.
- "Unknown artist", "Unknown album": why your MP3s show that and how to fix it
No tag, an old tag, a stale cache, a version the player can't read, or the wrong field: how to tell which and fix it.
- How to tag podcast episodes and audiobook MP3s so they play in order
Album, Artist, Title, Track and Genre settings that make spoken-word MP3s sort and play in order on any player.
- Title, Artist, Album Artist, Composer: which MP3 tag field does what
What each field is for, why Album Artist matters more than you'd think, and which ones you can safely leave blank.
- Hindi, Tamil, Arabic or Russian song titles showing as ???? or garbage: the encoding fix
Where the question marks come from (an encoding byte, an ID3v1 tag, or an old codepage) and the one-step fix.
- Mp3tag, Kid3, MusicBrainz Picard or a browser tool: which MP3 tag editor to use
Which tag editor fits which job: one file in a browser, a whole library in Mp3tag or Kid3, untagged rips in Picard.
- The full ID3v1 genre code list (0 to 191) and what to do when your genre isn't on it
All 192 codes in a table, which 80 are safe everywhere, and what to do when your genre isn't there.
- One album shows up as five: why players split albums and how to make them one again
Six reasons a player splits one album into several, and the checklist I use to make the tags identical again.
- How big should MP3 cover art be? I measured what each size adds to the file
JPEG vs PNG, 300 to 3000 pixels, measured on a real file. Where the sensible size is and why PNG is usually a mistake for photos.
- Album art not showing on Windows, iPhone, Android or in the car: every cause, in order
The seven reasons a cover you definitely embedded still won't appear, in the order to check them.