Guide
Fix MP3 Tags: Unknown Artist, Wrong Titles & Missing Album Art
7 min read
When a song shows up as "Unknown Artist" or "Track 01", the player is reading empty or wrong tags inside the file. Fix the tags, save the file, and replace the old copy. The audio tag editor lets you do that in your browser for MP3, M4A, FLAC and OGG files, without re-encoding the audio and without uploading anything.
Below: what tags actually are, which fields matter, how album art is stored, and how to get a stubborn player to show the new information.
Why songs show the wrong information
Music players do not guess from the file name. They read a block of text called a tag, stored inside the file next to the audio. In MP3 files that block is usually ID3; M4A, FLAC and OGG have their own versions of the same idea. If the block is empty, damaged, or full of typos, you get the symptoms you know:
- Unknown Artist or Unknown Album. The tags are empty, which is common for recordings, downloads from random sites and old rips.
- Wrong titles or "Track 01". The title field is empty or holds a leftover from a ripping program.
- One album split into several. Each track spells the album or artist slightly differently ("The Beatles" and "Beatles").
- Songs in the wrong order. The track number is missing, so the player falls back to alphabetical order.
- No artwork. The file has no embedded picture, or the picture is in a format or size the player dislikes.
The fields that matter
| Field | Why it matters |
|---|---|
| Title | What the player displays and searches by. |
| Artist | Groups songs under one name. Keep the spelling identical across tracks. |
| Album | Groups tracks into an album. Identical spelling again. |
| Track number | Controls the play order inside an album. |
| Year | Used for sorting and display by some players. |
| Genre | Used by smart playlists and some car stereos. |
| Cover art | The picture shown on the lock screen, in the app and on the car display. |
The editor covers exactly these seven. It does not have separate Album Artist or Disc Number fields, which matter for compilations and multi-disc sets. For those, see the desktop options further down.
Fix a song step by step
- Open the tag editor and select your MP3, M4A, FLAC or OGG file.
- The existing tags load automatically. Correct the title, artist, album, year, track number and genre.
- To fix the artwork, click Add cover or Replace cover and pick a JPG or PNG up to 5 MB. Remove cover deletes it.
- Click Save tags and download the file. The audio data is copied as it is, so the sound quality does not change.
- Replace the old file on your phone, USB stick or computer with the new one.
Only the fields you change are written. Anything you leave alone stays as it was, and a field you clear is removed from the file.
Tip: Name the artist and album once and copy the exact text for every other track on the album. Players group by exact text, so a stray space or capital letter creates a second album.
How cover art is stored
Embedded cover art is a small image saved inside the audio file itself. That is why it travels with the song when you copy it to another device. Separate files like folder.jpg only help on some desktop players.
Some practical points:
- Use JPG or PNG. Most players cannot show other image formats.
- A square image of about 500 by 500 pixels is a safe choice for car stereos and older players, and anything up to about 1400 pixels works in modern apps. Large images make files heavier and can confuse picky head units.
- MP3, M4A, FLAC and OGG can hold cover art. WAV and raw AAC files cannot, and the editor tells you so. If you need artwork, first convert such files to MP3, M4A or FLAC with the audio converter, then add the cover.
Why the old tags still show
Most players store a copy of your library's tags in a database and do not re-read the file every time. If you edit a song and still see the old information, the player is showing its cache, not your file. Try the steps for your device.
iPhone
If the songs were synced from a computer, replace them in the Music or Finder library on the computer and sync again. If the old version still appears, remove the song from the phone and add it again. The Music app can hold on to the information it first read, so deleting and re-adding is the dependable fix.
Android
Copy the new file over the old one, then restart the phone, which makes Android rescan its media. If the music app still shows the old data, clearing that app's cache usually forces it to reload; the exact menu varies by phone and app, so look under the app's storage settings. Moving the file to a different folder often makes it show up as a new song.
Windows and Mac
File Explorer and Finder read tags from the file, so they update quickly. Music apps with their own library, such as Windows Media Player or the Music app on a Mac, may need the song removed and re-added. Some desktop apps also have a refresh or rescan command.
Car stereos
Copy the new file to the USB stick again, and delete the old one first so there is no duplicate. If the screen still shows nothing, try a smaller cover image around 500 by 500 pixels. Some head units are fussy about large pictures or take a while to index a drive. Check your car's manual for its supported formats.
When to use a desktop tag editor instead
A browser tool is perfect for a handful of songs, but fixing a whole library one file at a time is slow. For hundreds of files:
- MusicBrainz Picard (free, Windows, Mac, Linux) can recognise songs by their sound and fetch tags and artwork from a large public database. Good when you have lots of tracks with no tags at all.
- Mp3tag (Windows, with a Mac version available) is excellent for bulk edits, such as setting the album for a whole folder at once, or turning file names into titles.
The browser editor is the faster choice for quick fixes on a phone or a borrowed computer, where installing software is not an option.
FAQ
Does editing tags reduce the audio quality?
No. Only the tag information is rewritten. The audio is copied without being decoded or re-compressed.
Can I add album art to a WAV file?
No. WAV files cannot hold embedded artwork in a way that players reliably read. Convert the file to MP3, M4A or FLAC first, then add the cover.
Why is my cover art not showing on my car stereo?
Often the image is too large or the car has not finished indexing the drive. Use a square JPG around 500 by 500 pixels, re-copy the file, and give the car a moment. Some head units do not display artwork at all.
Is my music uploaded when I edit tags?
No. The file is edited inside your browser and stays on your device. There is no sign-up and no watermark.
