Why Your iPhone Uses M4A
Every audio-related app on iPhone defaults to M4A format:
- Voice Memos: recordings are saved as M4A files with AAC encoding, typically at 48–96 kbps depending on the quality setting
- GarageBand: exports projects as M4A (AAC) when you share via AirDrop, Messages, or Mail
- iTunes Store purchases: songs are 256 kbps AAC in M4A containers, DRM-free since 2009
- Apple Music downloads: offline tracks are M4A with FairPlay DRM (cannot be converted)
Apple chose AAC because it delivers better audio quality than MP3 at the same file size. For most use cases, M4A is the superior format. But when you need MP3 — for a car stereo that only reads MP3 from USB, for a podcast platform, or for sharing with someone on a legacy device — conversion is straightforward.
Method 1: Online Converter (No App Required)
The fastest way to convert M4A to MP3 on iPhone. Works entirely in your browser — Safari, Chrome, or any other iPhone browser. No app download, no sign-up.
Step-by-step:
- Open Convertio.com in Safari or Chrome on your iPhone
- Tap "Choose Files" — select your M4A file from the Files app, iCloud Drive, or directly from Voice Memos (if you saved it to Files first)
- Choose encoding settings (optional) — the default VBR V2 (~190 kbps) is good for most music. For voice recordings, 128 kbps is more than enough
- Tap "Convert" — wait a few seconds for the server to process your file
- Tap "Download" — the MP3 file saves to your iPhone's Downloads folder (accessible via the Files app)
Tip: To find your downloaded MP3, open the Files app on iPhone and navigate to On My iPhone → Downloads. From there you can share the MP3 via AirDrop, Messages, Mail, or any other app.
Advantages: no app installation, no storage used by an app, works immediately, encrypted upload via HTTPS, files auto-deleted from the server within 2 hours.
Limitations: requires an internet connection. For very large files (1+ hour recordings), the upload time depends on your connection speed.
Method 2: Apple Music Built-In Encoder
If you have the Apple Music app (formerly iTunes) on your Mac, it has a built-in MP3 encoder. This method requires a Mac — it cannot be done directly on iPhone, but it is useful when you have access to a computer.
Step-by-step (macOS):
- Open Apple Music (or iTunes on older macOS versions)
- Go to Music → Settings → Files → Import Settings
- Change "Import Using" to MP3 Encoder
- Set quality to Higher Quality (192 kbps) or Custom → 256 kbps
- Select the M4A song(s) in your library
- Go to File → Convert → Create MP3 Version
- The MP3 copy appears in your library alongside the original
Limitations:
- Only works with DRM-free files — Apple Music subscription tracks cannot be converted
- Requires a Mac (not available directly on iPhone or iPad)
- Maximum quality is 320 kbps CBR — no VBR option in Apple's built-in encoder
- The built-in encoder uses Apple's own MP3 codec, which is not as advanced as LAME
Method 3: iOS Converter Apps
Several free and paid apps in the App Store can convert audio formats. Options include Audio Converter, The Audio Converter, and Media Converter. These work offline and can process files directly on your iPhone.
When apps make sense:
- You need to convert files frequently without internet access
- You want batch conversion of many files at once
- You need advanced settings not available in a web converter
Downsides:
- Most free versions have limitations (ads, file count limits, watermarks)
- Apps take up permanent storage space on your iPhone
- Quality varies — not all apps use high-quality encoders
- Some apps require in-app purchases to unlock basic features
Our recommendation: for occasional conversions, the web-based method is the best balance of convenience and quality. No storage used, no app to maintain, and the server uses the LAME encoder — the gold standard for MP3 encoding.
DRM Warning: What You Cannot Convert
Not all M4A files on your iPhone are convertible. Apple Music uses FairPlay DRM (Digital Rights Management) to protect subscription content:
| File Type | DRM Status | Can Convert? |
|---|---|---|
| iTunes Store purchases | DRM-free (since 2009) | Yes |
| Apple Music subscription | FairPlay DRM | No |
| Voice Memos | No DRM | Yes |
| GarageBand exports | No DRM | Yes |
| CD rips (via iTunes) | No DRM | Yes |
| Old iTunes DRM tracks | FairPlay DRM (pre-2009) | No |
If you have old iTunes purchases from before 2009 that still have DRM, you can upgrade them to DRM-free versions through iTunes (Apple charges a small fee per track). All purchases made after January 2009 are already DRM-free.
How to check for DRM: On a Mac, right-click the track in Apple Music, select Get Info, then look at the File tab. If the Kind says "Apple Music AAC audio file," it is DRM-protected. If it says "Purchased AAC audio file" or just "AAC audio file," it is DRM-free.
Converting Voice Memos Specifically
Voice Memos are the most common M4A files iPhone users need to convert. Here is the complete workflow:
Step 1: Export from Voice Memos
- Open the Voice Memos app
- Tap the recording you want to convert
- Tap the three-dot menu (...)
- Tap Save to Files — choose a location in iCloud Drive or On My iPhone
Step 2: Convert to MP3
- Open Convertio.com in Safari
- Tap Choose Files and navigate to where you saved the Voice Memo
- Upload and convert
Recommended quality settings for voice recordings:
| Content Type | Recommended MP3 Setting | File Size (1 min) |
|---|---|---|
| Voice memo (speech) | 128 kbps CBR | ~0.94 MB |
| Interview recording | 128 kbps CBR | ~0.94 MB |
| Lecture / meeting | 96 kbps CBR mono | ~0.70 MB |
| Music rehearsal | VBR V2 (~190 kbps) | ~1.4 MB |
Voice Memos typically record at 48–96 kbps AAC. Converting to 128 kbps MP3 preserves all the detail from the original source, since the MP3 bitrate exceeds the source bitrate. There is no benefit to using 320 kbps for a voice recording that was captured at 48 kbps — you would just create a larger file with no additional quality.
Alternative shortcut: In Voice Memos, tap the three-dot menu and choose Share. Instead of saving to Files first, you can copy the share link or use Open in Safari to go directly to a converter. However, saving to Files first gives you more control over the file.