- What's the difference between M4A and MP3?
- Both are compressed audio, but they use different codecs. M4A is an MP4 container that usually holds AAC audio — the format Apple picked for iTunes, Apple Music, and Voice Memos because it sounds a little better than MP3 at the same bitrate. MP3 is older and less efficient, but it plays on nearly everything ever built: 2008 car stereos, cheap Bluetooth speakers, office phone systems, and web forms that only list .mp3. Converting trades a small amount of efficiency for playing anywhere.
- Is my recording uploaded anywhere?
- No. The whole conversion runs inside your browser tab. The page reads the M4A from your disk, decodes the audio with your browser's built-in decoder, and encodes the MP3 with an encoder that runs on your device. Open your browser's network tab while it converts and you'll see nothing sent out. That matters for voice memos — interviews, therapy notes, and family recordings shouldn't sit on a stranger's server.
- Which quality should I pick?
- Match the bitrate to what's in the file. For speech — voice memos, lectures, interviews, podcasts — 128 kbps is clean and keeps files small, about 1 MB per minute of audio. For music, 192 kbps sounds as good as the original M4A to most listeners, about 1.4 MB per minute. Pick 320 kbps (about 2.4 MB per minute) only for music you'll play on good speakers. Going above the source doesn't add quality: a 128 kbps voice memo converted at 320 kbps gets bigger, not better.
- Will the MP3 sound worse than the M4A?
- Slightly, in theory. Both formats throw away sound you mostly can't hear, and converting from one to the other means the audio goes through a second round of compression. In practice, at 192 kbps or higher the difference is inaudible for almost everyone, and at 128 kbps speech sounds identical. If you need a perfect copy for editing, keep the original M4A and use the MP3 for sharing and playback.
- Why is my MP3 bigger than the M4A?
- Voice Memos records at a low bitrate — often around 64 kbps for mono audio — because AAC stays clear at small sizes. MP3 needs more bits to sound as good, so a 128 kbps MP3 of the same memo comes out roughly twice as large. That's expected. For music bought from iTunes (256 kbps AAC), a 192 kbps MP3 comes out smaller than the original.
- Do the song title, artist, and cover art carry over?
- Yes. The tags stored in the M4A — title, artist, album, and cover art — are written into the MP3 as standard ID3 tags, so the file shows up correctly in music players and car displays. Voice memos usually only have a title, which carries over too.
- Why won't my M4A convert?
- Three usual reasons. First, files ending in .m4p are copy-protected: old iTunes Store purchases or songs downloaded through an Apple Music subscription. No browser can decode them. Purchases can be downloaded again from your iTunes library as DRM-free .m4a files; subscription downloads stay locked. Second, some M4A files hold Apple Lossless (ALAC) audio instead of AAC — Voice Memos records this way when Audio Quality is set to Lossless — and browsers can't decode ALAC yet. On a Mac, the Music app can convert those directly (File → Convert → Create MP3 Version); on iPhone, switch Voice Memos back to Compressed for future recordings. Third, a file cut off mid-recording or mid-download can be missing the index that says where the audio is; export or download it again.
- How long can the recording be?
- Up to 3 hours and 4 GB per file. The limit comes from memory: the finished MP3 is held in your browser until you download it, and 3 hours at 320 kbps is about 412 MB. A full-length audiobook usually fits if you convert it chapter by chapter. There's no daily cap and no file count limit — convert as many as you like, one after another.
- Does it work on iPhone and Android?
- Yes, in a current version of Safari, Chrome, Edge, or Firefox. On an iPhone, Voice Memos don't show up in the file picker directly: open the memo, tap Share → Save to Files, then pick it from Files here. The MP3 downloads to your Downloads folder in Files. Long recordings convert faster on a laptop, since the work happens on your device.
