MP4 to M4A Converter
Convert MP4 to M4A free — no upload, no signup
To convert MP4 to M4A, drop your MP4 video 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. Most MP4 audio is copied into M4A without re-encoding.
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 MP4 to M4A
Add your MP4 videos
Drag and drop MP4 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 MP4 to M4A?
M4A gives you just the soundtrack in Apple's preferred format — perfect for iTunes, iPhone, podcasts and voice recordings.
What happens when you convert MP4 to M4A?
MP4 audio is usually AAC, so Fylo copies it straight into an M4A container — no quality loss, done in seconds. Other audio codecs are converted to AAC at 160 kbps.
How does Fylo convert MP4 to M4A?
Fylo decodes the soundtrack of the MP4 (usually AAC) with ffmpeg compiled to WebAssembly and encodes it with FFmpeg's AAC encoder at 160 kbps inside an MPEG-4 (M4A) container. The video stream is skipped entirely, which is why extraction is fast — the M4A is a fraction of the video's size. The original sample rate and channel layout are kept unless you change them under Advanced.
What's the difference between MP4 and M4A?
MP4 (MPEG-4 Part 14) is a container format standardised in 2001 and based on Apple's QuickTime file structure. A container holds separately compressed video and audio streams plus metadata such as subtitles, chapters and cover art. Most MP4s use H.264 video and AAC audio; newer files may use H.265 (HEVC) or AV1.
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: MP4 format guide · M4A format guide
| Property | MP4 | M4A |
|---|---|---|
| Type | Video | Audio |
| Contains | Video (H.264, H.265/HEVC, AV1) + audio (AAC, MP3) | Audio only, lossy (aac) or lossless (alac) |
| Developed by | MPEG (ISO/IEC 14496-14) | Apple / MPEG |
| Introduced | 2001 | 2003 |
| Compatibility | Universal: phones, TVs, editors, social media | Apple devices, Android, Windows 10+, browsers |
| Best for | Sharing, uploading, streaming, editing | iTunes/Apple Music libraries, voice memos, audiobooks |
Frequently asked questions
Is MP4 to M4A lossless?
Yes, when the MP4 has AAC audio and settings are left at default.
Why choose M4A over MP3?
No re-encoding, smaller files at the same quality, and native iPhone support.
Is my MP4 file uploaded to a server?
No. Fylo runs ffmpeg, the same engine used by professional video tools, compiled to WebAssembly inside your browser. Your MP4 file is read directly from your device and never sent anywhere.
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