Convert M4A to MP3
Your files are processed on your device. We never upload them.
Audio is read and written with Mediabunny. MP3 files are made with LAME and FLAC files with libFLAC; browsers without their own AAC encoder use FFmpeg's. Apple Lossless files follow Apple's ALAC code.
How to convert M4A to MP3
- 01A ▸Choose an M4A file, or drop it on the page. Voice Memos and iTunes songs work.
- 02A ▸Pick a quality. High (192 kbps) suits music; Smaller file is fine for speech.
- 03A ▸Select Convert to MP3, listen to the result, and download it.
About M4A to MP3
Where M4A files come from
M4A is the MP4 audio file Apple uses for iPhone Voice Memos, GarageBand exports, and iTunes downloads; inside is usually AAC audio. Many car stereos, older MP3 players, Windows apps, and upload forms don't accept it, so people convert it to MP3, which plays everywhere.
What changes
- The AAC sound is decoded and compressed again as MP3, so a little detail is lost. At 192 kbps or more it's very hard to hear.
- The title, artist, album, and cover picture are copied across. Chapter marks are not.
- The sample rate and mono or stereo stay the same; Voice Memos stay mono, which keeps the MP3 small.
- The MP3 is usually a little larger than the M4A at the same quality, because MP3 compresses less efficiently than AAC.
Measured
Our three-minute music-like sample (stereo, 44.1 kHz, the length of a typical song), saved as M4A (AAC, 128 kbps) and converted at the High setting (192 kbps) in Chrome on a laptop. Phone timings are still to be measured.
| M4A file | 2.8 MB |
|---|---|
| MP3 file | 4.1 MB |
| Time in Chrome (laptop) | 1.9 seconds, including loading the MP3 encoder |
In your browser
Chrome, Edge, and Safari 26 and later decode the AAC with their own built-in decoders, inside a background worker. Older Safari decodes it on the page with its audio engine instead. No browser can write MP3 itself, so the first conversion downloads a 0.1 MB MP3 encoder (LAME); later ones reuse it from the browser's cache.
Limits
- Apple Music downloads (protected M4P files) can't be converted.
- Lossless M4A (Apple Lossless) only converts in Safari.
- MP3 holds at most two channels, so surround M4A files are mixed down to stereo.
Other options
- Audio converter: convert M4A to WAV, FLAC, or OGG instead.
- Trim audio: cut the start and end off a Voice Memo, keeping it M4A or saving MP3.
- Voice recorder: record straight to MP3 on any device.
Questions
How do I get a Voice Memo off my iPhone?
In Voice Memos, tap the recording, tap the three dots, then Save to Files. Open this page in Safari on the iPhone and choose the file from Files, or send it to your computer with AirDrop and convert it there.
Are my recordings uploaded?
No. Your files are processed on your device. We never upload them.
Does converting M4A to MP3 lose quality?
A little, because the sound is decoded from AAC and compressed again as MP3. At High (192 kbps) or Best (320 kbps) the difference is very hard to hear. Choose a bitrate at least as high as the M4A's own.
Why convert to MP3 at all?
Some car stereos, older MP3 players, Windows apps, and upload forms accept only MP3. M4A sounds as good or better at the same size, so keep it when it plays where you need it.
My M4A is Apple Lossless. Does that work?
Lossless M4A (ALAC) converts in Safari on Mac, iPhone, and iPad. Chrome, Edge, and Firefox can't decode ALAC and say the file can't be read.
Can I convert songs bought from iTunes?
Songs bought from iTunes since 2009 have no copy protection and convert fine. Apple Music downloads are protected (M4P) and can't be converted.