Write metadata without touching the audio
Load a track, edit its fields, and save. The encoded audio is copied straight from the old file into the new one, so a 320 kbps MP3 comes out as the same 320 kbps MP3 with different tags attached. Nothing is decoded, which is also why saving takes about as long as reading the file.
The button counts the changes. Fields you do not touch are not written, they are carried through from the source.
What each container calls a tag
Metadata is not one standard, it is five, and which one applies is decided by the container the file is in.
- MP3 and ADTS use ID3v2 frames written at the head of the file, with
TIT2for title,TPE1for artist, and so on. - M4A uses atoms inside the MP4
metabox, the scheme iTunes established. - FLAC and Ogg use Vorbis comments, plain
KEY=valuetext pairs. - WAV uses chunks in a RIFF INFO list, which is the most limited of the five and the reason WAV files often lose their tags in transit.
The fields on this page are the common set, mapped onto whichever scheme the file uses. Anything a container holds that this form does not model, including replay gain and library identifiers, is preserved on the way through.
Cover art
One image is stored inside the file, tagged as front cover. Add one, replace one, or remove it entirely.
The size to aim for is 600 to 1000 pixels square in JPEG. That is enough for a phone lock screen and a desktop player, and small enough that the file does not grow noticeably. Artwork is duplicated in every copy of the track, which is why a 5 MB PNG is a poor choice even though it works.
Track and disc numbers
Both come in pairs: the position and the total. Players use them to sort an album, and a missing total is why a compilation sometimes plays in file name order instead. Leave a number at 0 to clear it.
Reading before writing
To inspect a file’s metadata, codec, and bitrate without changing anything, the metadata viewer reports all of it and copies the values out.