The Voice Memos app saves every recording as an .m4a file. That's fine on Apple devices,
but a podcast host, a course platform, a transcription service or an upload form may insist on MP3,
and some older car stereos and players won't play M4A at all. There's no "Save as MP3" button in
Voice Memos, so it takes two steps: get the file off the phone, then convert it.
We tested the conversion on 7 October 2026 on Windows 11 with Chrome, using a one-minute recording of speech saved the way phone recorders store voice: mono AAC at about 55 kbps, 424 KB. The steps for sharing from the iPhone and for the Mac's Music app come from Apple's documentation, not from our own test.
Step 1: get the memo off your iPhone
In Voice Memos, tap the recording, tap the … (more) button and choose Share. From there:
- Save to Files keeps it on the phone or in iCloud Drive, where a browser can pick it up.
- AirDrop sends it straight to a nearby Mac.
- Mail or a messaging app sends it to yourself so you can open it on a Windows PC.
Whichever you choose, what arrives is an ordinary .m4a file, usually named after the memo.
Step 2: convert it
| Method | Works on | Good to know |
|---|---|---|
| M4A to MP3 in the browser (free) | Any computer; tested in Chrome on Windows | Nothing to install, nothing uploaded, several memos at once. Keeps the title tag and picks a bitrate to suit the recording. |
| Music app on a Mac | macOS | Apple's documented route: add the memo to your library, set the import format to MP3, then create an MP3 version. It changes a library setting, so switch it back afterwards. |
| Converter apps on the iPhone | iOS | Many exist, often with ads or subscriptions, and some send the file to a server. We didn't test them. |
In the browser: open M4A to MP3, drop the file in and download the MP3. Our one-minute memo took about a second. The converter runs on your own computer, so the recording isn't sent anywhere, which matters when a memo holds an interview, a meeting or a private note.
On a Mac with the Music app (from Apple's support article on converting M4A to MP3): choose File > Import to add the memo to your library, then go to Music > Settings > Files > Import Settings and set Import Using to MP3 Encoder. Select the memo and choose File > Convert > Create MP3 Version. The MP3 appears next to the original in your library; drag it out to a folder to send it.
Step 3: pick settings for speech, not music
This is where most guides stop, and it's where file size is decided. A voice memo is one person on one microphone, so it's mono, and speech doesn't need the bitrate music does. We converted our one-minute memo four ways:
| MP3 setting | File size for 1 minute | Compared with the M4A (424 KB) |
|---|---|---|
| 64 kbps, mono | 481 KB | 1.1× |
| 80 kbps, mono (the converter's automatic choice) | 601 KB | 1.4× |
| 128 kbps, stereo | 961 KB | 2.3× |
| 320 kbps, stereo | 2.40 MB | 5.7× |
Stereo stores the same voice twice, and 320 kbps spends a music budget on a voice that was recorded at about 55 kbps. Neither can sound better than the memo itself. For speech, 64 kbps mono is enough. The automatic setting goes a little higher because MP3 is less efficient than the AAC inside the M4A. The MP3 is a little larger than the M4A either way: that's the price of the more compatible format.
Those sizes also tell you how much fits under common limits. At 64 kbps mono, a 25 MB email attachment holds about 52 minutes of recording; at 128 kbps stereo, about 26 minutes. A one-hour interview at 64 kbps mono is about 29 MB.
Cut it first if you only need part of it
If the useful part is three minutes in the middle of a long recording, trim it before you convert. Trim audio cuts an M4A without re-encoding it, so the clip keeps the original quality, and the converter then has less to process and the MP3 is smaller. Converting first and trimming the MP3 afterwards works too, but the MP3 is then cut at MP3 frame boundaries.
What carries over
The converter copies the M4A's tags into the MP3. Our test memo had the title "Monday errands", and the MP3 kept it at every setting, so it shows up with that name in music players and on car screens rather than as a file name. Length stayed the same: 60.01 seconds in, 60.01 seconds out.
WhatsApp and Telegram voice notes are different
Voice notes from messaging apps usually arrive as .ogg or .opus, not M4A. The
same converter takes them, but Opus is so efficient for speech that the MP3 comes out bigger: in our
test a 20-second note doubled from 80 KB to 160 KB. Convert those only when the place you're sending
them to needs MP3.