M4A is the audio-only cousin of MP4. Apple uses it everywhere: iPhone Voice Memos, songs bought in the iTunes Store, GarageBand exports and audio shared from many iPhone apps. Zoom saves an M4A when you record a meeting locally, and many Android voice recorders do the same. It sounds good and files are small, but plenty of places still want MP3: older car stereos and MP3 players, some podcast and transcription services, voiceover marketplaces, school and court upload forms, and colleagues on older Windows setups.
This converter changes M4A files to MP3 on our server. It also takes AAC, WAV, OGG, Opus, FLAC and WMA audio, and the sound track of video files, so one page covers most "this audio will not play" problems.
How to convert M4A to MP3
- Drop the M4A onto the box above, or click it to choose a file. On an iPhone, tap the box and pick the file from Files. The drop box shows today's size and length limits.
- Pick the MP3 quality: 128, 192 or 320 kbps. If your browser can read the file, the line below shows its length, the expected MP3 size, and a hint if your file's own bitrate is lower than the one you picked.
- Click Convert to MP3. The progress bar shows the upload, then your place in line if the server is busy, then the conversion.
- The MP3 downloads when it is ready. The result screen has a player, so you can check the sound before you close the page.
- For the next recording, click Convert another file.
Getting Voice Memos off your iPhone
Voice Memos does not show its files in the Files app by default, so the first step is getting the M4A out:
- Open Voice Memos and tap the recording.
- Tap the three dots (More), then Share.
- Choose Save to Files and pick a folder, such as On My iPhone > Downloads. The file is saved as an M4A with the recording's name.
- Open this page in Safari, tap the box and choose that file from Files.
On a Mac, open the Voice Memos app and drag a recording to the desktop to get the M4A. If you record often, check Settings > Apps > Voice Memos > Audio Quality: Compressed is the default and right for speech, while Lossless keeps every detail for music and interviews at several times the file size. Both save as .m4a; this converter handles either.
Converting on an Android phone
- Find the recording in your recorder app and use its Share or Save option to put the M4A in Downloads or Files. Samsung's Voice Recorder keeps recordings in a Voice Recorder folder on the phone storage.
- Open this page in Chrome, tap the box and pick the file from Files or Downloads.
- When the MP3 is ready, it saves to Downloads. Share it from there to email, WhatsApp or Drive.
Which MP3 bitrate to choose
| MP3 quality | Size per minute | Best for |
|---|---|---|
| 128 kbps | about 0.9 MB | Voice memos, lectures, meetings, interviews, podcasts |
| 192 kbps | about 1.4 MB | Music and mixed content; a safe default |
| 320 kbps | about 2.3 MB | Music from a high quality or lossless M4A |
Match the bitrate to the source
Most M4A files contain AAC, which is already compressed. Converting AAC to MP3 is a second round of lossy compression: the MP3 can be as good as the M4A at best, never better. A voice memo recorded at a modest bitrate gains nothing from 320 kbps; it just becomes a bigger file. When the page can read your file, it tells you the M4A's current bitrate and warns when you pick a much higher one. Songs bought from the iTunes Store are 256 kbps AAC, so 320 kbps keeps them closest to the original, and 192 kbps is hard to tell apart on most speakers.
If your M4A is Apple Lossless (ALAC), the source is not compressed at all, and any MP3 bitrate is the first and only lossy step. 192 or 320 kbps are both excellent choices there.
Note: Songs downloaded through an Apple Music subscription are protected and cannot be converted by any tool. Songs you bought in the iTunes Store are not protected and convert normally.
What is inside an M4A
| Inside the M4A | Typical source | Converting to MP3 |
|---|---|---|
| AAC (lossy) | Voice Memos on Compressed, iTunes Store songs, Zoom audio, Android recorders | Second lossy step; match or exceed the original bitrate |
| ALAC, Apple Lossless | Voice Memos on Lossless, CD rips in the Apple Music app | First lossy step; 192 or 320 kbps |
| Protected AAC (.m4p) | Apple Music subscription downloads | Cannot be converted |
The file name does not tell you which one you have. On a Mac, select the file and choose File > Get Info in Finder to see the codec under More Info; VLC shows it under Tools > Codec Information on any computer.
Where M4A works and where MP3 is still needed
M4A plays on iPhones, Macs, Android phones, Windows 10 and 11, and in Chrome, Safari, Edge and Firefox. Converting is not always necessary. MP3 is still the safer choice for:
- Car stereos and older MP3 players, many of which read MP3 from a USB stick but skip M4A.
- Upload forms that list MP3 or WAV only, common on voiceover marketplaces, music contests, school portals and some transcription services.
- Older Windows software such as legacy dictation and editing programs.
- Sharing with people whose devices you do not know. Every device made in the last 25 years plays MP3.
Worked examples
An interview recorded with Voice Memos
A 42 minute interview recorded on an iPhone is a 40 MB M4A. The transcription service you use accepts MP3 only. At 128 kbps the MP3 is about 38 MB, nearly the same size, and the speech sounds the same. Check the length limit in the drop box first: long recordings may need to be split into parts in an editor such as Audacity before converting.
A Zoom audio file for a podcast editor
Zoom's local recording saves the meeting video plus an audio-only M4A. Your editor wants MP3. Convert at 192 kbps for a mixed recording with music, or 128 kbps if it is all speech. For tighter sound, AM Jarvis Voice Studio has a Clean audio step for recordings you made yourself: it removes low rumble, reduces steady noise such as fans, trims silence at the start and end and evens out the loudness. It accepts M4A directly, up to 30 minutes and 100 MB.
An album from the iTunes Store for an old car stereo
Ten songs bought in the iTunes Store are 256 kbps M4A. Convert each one at 320 kbps, copy the MP3s to a USB stick, and the car plays them. The tool takes one file per job, so convert the songs one after another with Convert another file.
A voice note from an Android recorder
Samsung's Voice Recorder and many other Android recorders save M4A. A 3 minute note becomes a 2.8 MB MP3 at 128 kbps, small enough for any email or messaging app.
A lecture recorded on an iPad for classmates
A student records a 55 minute lecture with Voice Memos on an iPad and wants to share it with a study group that mixes Windows laptops and Android phones. M4A would play for most of them, but an MP3 at 128 kbps plays for all of them, at about 53 MB. If that is over the free length limit, split the lecture at the break into two parts in an editor and convert both.
What the MP3 contains
- The full recording, start to finish, with the same length.
- The same channels: a mono voice memo stays mono, a stereo song stays stereo.
- Title and artist tags from the M4A in most cases. Check them in your music app; album artwork embedded in the M4A is not copied, so add it there if you need it.
- A file name based on the original, ending in .mp3.
Sending the MP3 on
- Email: 128 kbps speech is about 1 MB per minute, so recordings up to about 20 minutes fit a 25 MB attachment.
- WhatsApp and Telegram: send the MP3 as a document or file, not as a voice message, so it arrives unchanged and with its name.
- Between Apple devices: AirDrop the MP3 from Files; it opens in Files or Music on the other device.
- To a podcast host or editor: upload the MP3 directly, or keep the original M4A if the host accepts it, since it skips one compression step.
Privacy and limits
The file goes to our conversion server over HTTPS, together with the bitrate you chose and nothing else. The upload is deleted as soon as the job ends, and the MP3 30 minutes after it is ready. After the first download, the Download button keeps a copy in your open tab. Free use has a daily count shown under the tool and a size and length limit shown in the drop box. For a recording that is still in a video file, the MP4 to MP3 converter does the same job, WAV to MP3 covers studio exports, and OGG to MP3 handles voice messages from Discord, Telegram and WhatsApp.
Other ways to convert M4A to MP3
- Apple Music app on a Mac: Music > Settings > Files > Import Settings, set Import Using to MP3 Encoder, then select songs and choose File > Convert > Create MP3 Version. Works for songs in your library.
- Audacity (free): install its free FFmpeg library (Audacity's preferences link to it), open the M4A, then File > Export Audio as MP3. Useful if you want to edit too.
- ffmpeg:
ffmpeg -i input.m4a -b:a 192k output.mp3. - This converter: works on an iPhone, Android phone or Chromebook with nothing to install, and shows the expected size first.
Troubleshooting
The expected size does not appear
Some browsers cannot read every M4A for a preview. The conversion still works on the server.
"This file could not be used"
The file may be protected (an Apple Music download), incomplete, or not really an M4A. Try playing it in VLC. Protected files cannot be converted.
The MP3 sounds worse than the M4A
Convert again at a higher bitrate, at least as high as the M4A's own bitrate. For speech, 128 kbps is plenty; for music, use 192 or 320 kbps.
I cannot find the MP3 on my iPhone
Safari saves downloads to the Downloads folder in the Files app. Open Files, tap Browse, then Downloads. To change the folder, use Settings > Apps > Safari > Downloads.
The voice memo is very quiet
The converter keeps the volume as recorded. Raise it in an editor with Normalize, or use Voice Studio's Clean audio, which sets an even loudness.
"This file is too long"
Split the recording into parts in an audio editor, then convert each part. The limit is shown in the drop box.