Free · no signup · never uploaded
M4A to MP3 Converter
Convert an Apple .m4a audio file into a universally-playable 192 kbps MP3 — in your browser, no upload.
Short answer
To convert M4A to MP3, drop your .m4a file below and download the MP3. M4A (AAC audio) is what Apple Music, Voice Memos, and iTunes use; converting to MP3 makes it play everywhere. It runs in your browser with ffmpeg — nothing is uploaded.
What is an M4A file?
M4A holds AAC audio in an MP4 container — the format Apple uses for Voice Memos, Apple Music, and iTunes downloads. It’s efficient, but some players and car stereos only accept MP3, so converting makes the audio universally playable.
Any quality loss?
Both M4A and MP3 are lossy, so converting re-encodes the audio once at 192 kbps. For a single conversion the difference is inaudible to most listeners, and you gain compatibility with virtually every device and app.
MP3 bitrate, size and quality
| Bitrate | Per minute | Per hour | Best for |
|---|---|---|---|
| 128 kbps | 1.0 MB | 58 MB | Speech, podcasts, voice notes |
| 192 kbps | 1.4 MB | 86 MB | Music — transparent to most listeners — used by these tools |
| 256 kbps | 1.9 MB | 115 MB | Music on good headphones |
| 320 kbps | 2.4 MB | 144 MB | The maximum MP3 allows |
MP3 file size is almost purely bitrate × duration, so you can predict it exactly: a three-minute song at 192 kbps is about 4.3 MB regardless of what the original was. Above roughly 192 kbps most listeners cannot pick MP3 from the original in a blind test.
How we calculate this
Conversion happens locally in your browser with ffmpeg — here is exactly how:
- Load the engine. ffmpeg compiled to WebAssembly loads once in your browser from this site (self-hosted, not a third party) — your file is never uploaded.
- Decode. ffmpeg reads the M4A file and decodes its audio (any video stream is dropped with -vn).
- Encode to MP3. the audio is re-encoded to MP3 at 192 kbps constant bitrate and handed back as a download.
Assumptions
- Everything runs client-side; speed depends on your device and the clip length.
- MP3 is lossy at 192 kbps and cannot exceed the quality of the source audio.
- Very large or long files are limited by your browser's available memory.
Last reviewed: July 19, 2026
Frequently asked questions
How do I convert M4A to MP3?+
Drop your .m4a file in above and download the MP3 the tool creates. The whole conversion runs in your browser with ffmpeg, so your file is never uploaded. The first conversion loads the converter (about 31 MB) once; after that it's instant.
Are my files uploaded to a server?+
No. Everything runs 100% in your browser using ffmpeg compiled to WebAssembly, so your file never leaves your device. Nothing is stored or sent anywhere — it's private and works offline once the converter has loaded.
What quality is the MP3?+
The audio is encoded at 192 kbps constant bitrate — a high-quality setting that sounds great for speech and music while keeping the file small. It's a good balance for podcasts, lectures, and songs.
Why is the first conversion slower?+
The first time, your browser downloads the ffmpeg engine (about 31 MB) and starts it up. That happens once — later conversions in the same session reuse the loaded engine and are much faster.
Is there a file-size limit?+
There's no fixed limit, but because the conversion runs in your browser's memory, very large or long files can be limited by your device's available RAM. Most typical files convert without any issue.
Is it free?+
Yes — no signup, no watermark, no per-file limit. It's ad-supported and runs entirely in your browser.
Related tools
- MP4 to MP3 — extract audio from an MP4 video.
- WAV to MP3 — compress a WAV recording to MP3.
Audio is converted entirely in your browser with ffmpeg and never uploaded. MP3 is encoded at 192 kbps.