Convert MP3 to M4A
Turn an MP3 into an AAC M4A file that drops neatly into iTunes, Apple Music, and the Music app on iPhone. It all runs in your browser, so nothing is uploaded.
Why convert MP3 to M4A?
M4A is the format Apple prefers, so people convert to it when they want files that behave in iTunes, Apple Music, and the Music app on iPhone and iPad. AAC is also a touch more efficient than MP3 at the same bitrate, which helps most below 192 kbps. If you are tidying a library so everything matches, or you want ringtones and clips that play cleanly across your Apple devices, M4A is the natural target. It stays broadly compatible, though very old hardware sometimes still favors plain MP3.
Quality and file size
This is a lossy to lossy conversion, so it is transcoding: the MP3 is decoded and then re-encoded as AAC, which adds a small amount of generation loss on top of what the MP3 already lost. To keep that as quiet as possible, choose 256 or 320 kbps for the M4A rather than a low bitrate. It will not sound better than the source, because it cannot; the goal is Apple compatibility with minimal added loss. Also avoid repeated round-trips between lossy formats, since each pass chips away a little more.
MP3 to M4A: common questions
Is MP3 to M4A lossless?
No. Both are lossy formats, so this re-encodes the audio and adds a little generation loss. Choosing 256 or 320 kbps keeps that loss small enough that most listeners will not notice.
Why convert MP3 to M4A at all?
M4A is the default across Apple software and devices, so it slots cleanly into iTunes, Apple Music, and iPhone. AAC is also slightly more efficient than MP3 at the same bitrate, especially below 192 kbps.
Does my file get uploaded to a server?
No. The conversion runs locally in your browser with FFmpeg in WebAssembly. Your MP3 never leaves your device, and we never receive, store, or train on it.
What bitrate should I pick?
Use 256 or 320 kbps. Since you are re-encoding already-lossy audio, a higher bitrate limits the extra loss, and it is best to avoid converting back and forth between lossy formats repeatedly.
Who makes this?
We're the small team behind Xport Studio, a private, fully offline app for AI vocals, stems, and mastering. These free tools are side experiments we wanted to share. No upsell, but if you're curious about the bigger thing, take a look.