MP3 to M4A Converter
Runs in your browser — your files are never uploaded.
Convert MP3 audio to M4A. The usual reason is somewhere that wants AAC specifically — setting a custom iPhone ringtone, importing into GarageBand, or satisfying an upload form that rejects .mp3. Runs entirely in your browser using a real build of ffmpeg compiled to WebAssembly.
OptionsBitrate: Default — best quality for size
How to convert MP3 to M4A
- 1
Drop your .mp3 file onto the box, or click to choose one.
- 2
OkConverter loads the conversion engine (one-time per session) and re-encodes as AAC.
- 3
Click “Download” to save the .m4a file.
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Frequently asked questions
Does converting MP3 to M4A improve the sound?+
No. This is one lossy format to another, so a little more detail is lost, not gained. Do it when you need the format, not to make the audio better — and if you still have the original WAV or FLAC, convert from that.
Can I use this to make an iPhone ringtone?+
It gets you the right audio format. iOS ringtones also need the .m4r extension and a length under 40 seconds, so trim it with the Audio Trimmer first and rename the result from .m4a to .m4r.
What bitrate is the output?+
192kbps AAC. Since your MP3 is likely 128–320kbps already, expect a similar file size — this is a format change rather than a compression exercise.
Is my file uploaded anywhere?+
No. Once the engine has loaded, the whole conversion happens inside your browser tab.