About M4A to MP3
M4A is the audio format Apple devices use for voice memos and many downloaded tracks. It's usually AAC audio inside an MPEG-4 container, which sounds good but isn't accepted by every older player, car stereo or upload form. This converter decodes M4A files with your browser's built-in audio support and re-encodes them as MP3 at the bitrate you choose. Mono works well for voice memos and halves the file size. Convert interviews, lectures or songs in one batch and download them as a ZIP, all without the audio leaving your device.
How to Use It
- 01
Add M4A files
Drop .m4a files in the box, or tap to pick them from your files app.
- 02
Choose bitrate and channels
Use 128 kbps mono for speech, or 192 kbps stereo and above for music.
- 03
Save the MP3s
Press Convert and download individually or as one ZIP.
What is an M4A file?
M4A is an audio file using AAC compression inside an MPEG-4 container, the same family as MP4 video. Apple uses it widely: iPhone Voice Memos, iTunes and Apple Music downloads without DRM, GarageBand exports and many podcast and recording apps save audio as M4A. It sounds good at small sizes, often better than MP3 at the same bitrate.
The problem is compatibility. Some car stereos, older MP3 players, DJ software, phone systems, transcription services, video editors and upload forms only accept MP3. Converting fixes that in seconds. Read more in the M4A format guide.
Choosing a bitrate
Bitrate controls quality and size. For music, 192 kbps is a good balance that most people can't tell from the original, and 256–320 kbps is the choice for the best quality. For speech, such as voice memos, lectures, interviews and podcasts, 96–128 kbps sounds clear and keeps files small.
Choosing a bitrate higher than the original doesn't improve the sound; it only makes the file bigger. An iPhone voice memo is usually around 64 kbps AAC, so 96 or 128 kbps MP3 is plenty.
Stereo or mono?
Keep stereo for music. For recordings of a single voice, choose mono: the file is half the size with no loss in clarity, because both channels of a voice recording contain almost the same sound anyway. This is the best way to make long recordings small enough to email or upload.
M4A vs MP3: which sounds better?
At the same bitrate, AAC in an M4A file usually sounds slightly better than MP3, especially at low bitrates around 96–128 kbps, because AAC is the newer codec. In practice, at 192 kbps and above the difference is very hard to hear. Converting from M4A to MP3 means decoding one lossy format and encoding another, so choose a bitrate at least as high as the original to avoid an audible drop in quality. Keep the M4A if you only listen on Apple devices, and use MP3 for everything else.
Converting iPhone voice memos
To get a voice memo off your iPhone, open the Voice Memos app, tap the recording, tap the three-dot menu and choose Save to Files. Then tap the box above, pick the file from the Files app, convert it to MP3 and save the result. On a Mac, you can drag recordings out of the Voice Memos app directly. Several files can be converted together and downloaded as a ZIP.
Song titles, artist names and cover art stored in the M4A aren't copied to the MP3, so add them afterwards in your music app if you need them. To shorten a recording before sharing it, use Trim Audio. For uncompressed recordings, see WAV to MP3.
Questions
Why convert M4A to MP3 at all?
MP3 has the widest compatibility of any audio format. Some car stereos, older MP3 players, and websites only accept MP3 files.
Can it convert Apple Lossless files?
Only if your browser can decode Apple Lossless (ALAC), and support varies. AAC-encoded M4A files, which are the most common, work in current major browsers.
Do DRM-protected purchases work?
No. Copy-protected tracks can't be decoded by the browser, so they can't be converted.
Will the MP3 sound worse than the M4A?
AAC and MP3 are both lossy, so there's a small loss when converting. Choose a bitrate equal to or higher than the original to keep it minimal.