M4A to MP3 Converter
Convert Apple M4A and AAC audio to MP3.
File
Result
Your converted file will appear here.
About the M4A to MP3 converter
M4A is the container Apple uses for AAC audio — iPhone voice memos, GarageBand bounces, iTunes purchases. It is a better codec than MP3, but plenty of hardware and older software simply will not open it.
Converting to MP3 trades a little efficiency for the ability to play the file anywhere.
Voice memos and interviews
Speech recordings are the most common M4A files people need to convert, usually to feed into transcription software or a podcast editor that expects MP3.
For voice, turn on mono and pick 96 kbps. The result is a fraction of the size with no meaningful loss of intelligibility, and transcription accuracy is unaffected.
Choosing a bitrate
192 kbps is the sensible default for music — most listeners cannot reliably tell it from the source on ordinary equipment. 320 kbps is the ceiling MP3 allows and worth it if the file is going to be archived or edited further.
For speech — interviews, lectures, podcasts, voice notes — 96 kbps mono is plenty and produces a file several times smaller. Music at that rate starts to sound obviously thin, particularly in cymbals and reverb tails.
How the conversion works
Your browser decodes the file with the Web Audio API — the same decoder it uses to play media — which hands back raw PCM samples. Those samples are then re-encoded into the output format.
MP3 encoding uses LAME compiled to JavaScript, running in a background worker so a long file does not freeze the page. Nothing is uploaded: no server sees the audio, there is no queue, and there is no processing limit beyond your own device.
Frequently asked questions
Will my tags and album art carry over?
No. The conversion works on the decoded audio, so metadata is not transferred. Add tags afterwards in your music player or a tag editor.
Will converting reduce the quality?
Re-encoding lossy audio always loses a little, because the encoder is working from what survived the first compression rather than from the original. Keep the bitrate at or above the source and it will not be audible. Converting from a lossless source such as WAV or FLAC has no such problem.
Can it convert protected iTunes purchases?
No. DRM-protected files cannot be decoded by the browser at all, and removing that protection is not something this tool does.
Is my file uploaded?
No. Decoding and encoding both happen in your browser. The audio never leaves your device, which is why there is no size limit imposed by a server.