M4A to MP3
Convert M4A audio, including iPhone Voice Memos, to MP3. Nothing is uploaded.
Drop M4A files here
Converted on your device. Files are never uploaded.
Up to 20 files at a time.
M4A is what iPhones, Voice Memos and iTunes use for audio, but plenty of players, editors and websites ask for MP3 instead. FormatJet converts M4A to MP3 in your browser, so recordings of meetings, lectures and family moments stay on your device from start to finish.
About the formats
M4AM4A audio
M4A is an MP4 file that holds only audio, usually AAC. iPhones, iTunes and voice recorders use it; files are smaller than MP3 at the same quality, but some players and sites only take MP3.
MP3MP3 audio
MP3 is the most widely supported audio format. Its lossy compression makes music about a tenth of the size of a CD, and every phone, car and player can play it.
Converted with Mediabunny, Browser audio decoder (WebCodecs), LAME MP3 encoder, Media engine (FFmpeg).
Questions
Can I convert iPhone Voice Memos?
Yes. Voice Memos saves recordings as M4A, so add a memo here once it’s saved as a file and you get an MP3 back.
My audio file ends in .mp4. Can I use it here?
Yes. An M4A is simply an MP4 that holds only audio, so this page also takes audio-only files saved with the .mp4 extension. For an MP4 with video in it, use MP4 to MP3.
Will converting M4A to MP3 reduce quality?
Slightly. The AAC in an M4A was compressed with loss when it was made, and MP3 encoding is a second lossy pass over it. Choosing a higher bitrate in Options, rather than the default 192 kbps, keeps more of the original.
Why does this need a recent browser?
The AAC audio is decoded by your browser’s own built-in decoder, part of WebCodecs. Current Chrome, Edge, Firefox and Safari all have it; if yours can’t decode the file, the page says so rather than converting.
M4A to MP3 with the API
The conversion API opens later this year.
curl https://api.formatjet.com/v1/convert?to=mp3 \
-H "Authorization: Bearer fj_test_…" \
-F file=@input.m4a -o output.mp3