How to Convert M4A to MP3 on iPhone Without a Computer
Convert Voice Memos and M4A files to MP3 directly on your iPhone. Step-by-step guide using a browser converter — no app download, no computer needed.
Your iPhone records Voice Memos as M4A files. GarageBand exports M4A. Most iPhone audio is M4A. Most of the rest of the world wants MP3. Here's how to convert directly on your iPhone, no computer or app install needed.
What You Need
- iPhone with iOS 15.4 or later (Safari supports the WebAssembly needed for conversion)
- The M4A file on your device — from Voice Memos, Files app, iCloud Drive, or shared by someone
Step-by-Step: Convert Voice Memo to MP3 on iPhone
1. Get the M4A file into Files
If the file is in Voice Memos, open Voice Memos, tap the recording, tap the three-dot menu (•••), and tap Share. Choose Save to Files and save it somewhere you can find it.
If someone AirDropped you an M4A or you downloaded it from email, it's already in Files → Downloads.
2. Open the converter in Safari
Open Safari and go to audioutils.com/m4a-to-mp3. This runs entirely in your browser — no app download.
3. Select the M4A file
Tap "Select your file". The iOS file picker opens. Navigate to where you saved the M4A (Files → Recents, or wherever you saved it). Tap it to select.
4. Convert
The converter processes the file locally on your iPhone. You'll see a progress bar. For a typical Voice Memo (a few minutes long), this takes 5–15 seconds.
5. Download the MP3
Tap the Download button. iOS saves the MP3 to your Downloads folder in Files (Files → Browse → Downloads).
6. Share or use the MP3
From Files → Downloads, tap the MP3 file, then tap the Share icon (square with arrow up) to:
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Does It Work on Older iPhones?
The converter requires iOS 15.4+ for full WebAssembly support. If you're on an older version, you'll see a warning. In that case, your options are:
- Update iOS if possible (Settings → General → Software Update)
- Transfer the M4A to a Mac and use the MOV to MP3 on Mac approach — which also works for M4A files
Free vs Pro
The free tier outputs the first 30 seconds of the conversion. For Voice Memos and GarageBand exports that are just a few seconds, this is fine. For longer recordings, there are two options:
- Upgrade to Pro ($9/month): unlimited length, files up to 500 MB
- Trim the Voice Memo first: in Voice Memos, edit the recording to keep only the part you need, then convert the trimmed version
Can I Use This for GarageBand Exports?
Yes. GarageBand on iPhone exports projects as M4A. Share the GarageBand file to Files as M4A, then convert to MP3 using the same steps above.
What About Chrome on iPhone?
Chrome on iOS uses the same underlying WebKit engine as Safari, so it should also work for this conversion. If you run into issues, Safari is the more reliable choice on iOS.
Why M4A and Not MP3 by Default?
M4A (which wraps AAC audio) is technically superior to MP3 at the same bitrate — better quality, smaller file. Apple defaults to M4A because it's more efficient. The problem is compatibility: older Android phones, car stereos, some podcast hosts, and many sharing platforms still expect MP3 specifically. Converting to MP3 at 128–192 kbps gives you a file that plays everywhere.
For just sharing a Voice Memo to another iPhone user via iMessage, you don't need to convert — M4A plays fine on all Apple devices. Convert to MP3 when the recipient is on Android or Windows, or when the destination (podcast host, web form, etc.) requires MP3.