MP3 to M4A Converter
Convert MP3 to M4A free — no upload, no signup
To convert MP3 to M4A, drop your MP3 audio files into the box below and click Convert. Fylo converts with ffmpeg running inside your browser, so nothing is uploaded and there's no signup or watermark. M4A gives you AAC audio with tags that iTunes and iPhones love.
Drop audio files here
or tap to browse · paste with Ctrl+V · add many at once
Your files never leave your device
Advanced
How to convert MP3 to M4A
Add your MP3 files
Drag and drop MP3 files into the box or tap to choose them. The converter engine (about 31 MB) downloads once, the first time you convert.
Pick a bitrate
192 kbps suits music and 128 kbps or less suits speech. Sample rate and mono/stereo are under Advanced.
Convert and download
Click Convert, then download each M4A file or all of them as one ZIP.
Why convert MP3 to M4A?
Apple Music, iTunes and GarageBand libraries are built around M4A. Converting MP3s lets you keep a consistent format, and M4A is the starting point for iPhone ringtones.
What happens when you convert MP3 to M4A?
Fylo re-encodes the MP3 to AAC at 160 kbps in an M4A container. File size is similar to the MP3; there's a small, usually inaudible, generation loss.
How does Fylo convert MP3 to M4A?
Fylo decodes the MP3 audio in the MP3 with ffmpeg compiled to WebAssembly and encodes it with FFmpeg's AAC encoder at 160 kbps inside an MPEG-4 (M4A) container. Both formats are lossy, so each conversion discards a little detail — start from the highest-bitrate MP3 you have. A 3-minute song is ≈ 4.3 MB at 192 kbps as MP3 and ≈ 3.6 MB at 160 kbps as M4A. The original sample rate and channel layout are kept unless you change them under Advanced.
What's the difference between MP3 and M4A?
MP3 (MPEG-1 Audio Layer III) was developed largely at Germany's Fraunhofer Institute and standardised in 1993. It removes sounds the ear is unlikely to notice — a technique called perceptual coding — so a 3-minute song takes about 4 MB at 192 kbps instead of about 32 MB as WAV. The last MP3 patents expired in 2017, so it's now free to use.
M4A is an MPEG-4 container that holds only audio — usually AAC, or Apple Lossless (ALAC). Apple popularised the extension with the iTunes Store in 2003; iPhone Voice Memos and many podcasts also use it. Audiobooks often use the related .m4b extension.
Learn more: MP3 format guide · M4A format guide
| Property | MP3 | M4A |
|---|---|---|
| Compression | Lossy | Lossy (AAC) or lossless (ALAC) |
| Typical bitrate | 128–320 kbps | 128–256 kbps |
| 3-minute song | ≈ 4.3 MB at 192 kbps | ≈ 3.6 MB at 160 kbps |
| Tags and cover art | Yes (ID3) | Yes (full, with cover art) |
| Compatibility | Universal | Apple devices, Android, Windows 10+, browsers |
| Best for | Music and podcasts on any device | iTunes/Apple Music libraries, voice memos, audiobooks |
| Introduced | 1993 | 2003 |
Frequently asked questions
Will iTunes accept the M4A?
Yes, it's the standard iTunes format.
Can I make an iPhone ringtone?
Yes — use the Ringtone Maker, which cuts to 30 seconds and saves M4R.
Is my MP3 file uploaded to a server?
No. Fylo runs ffmpeg, the same engine used by professional video tools, compiled to WebAssembly inside your browser. Your MP3 file is read directly from your device and never sent anywhere.
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