Extract M4A Audio from MP4
Pick an .mp4 and get its first audio track as .m4a — a lossless stream-copy remux with no re-encode. Runs in your browser, nothing is uploaded.
Extract the audio track from an MP4 as M4A
An .mp4 video is a container: it often holds H.264/HEVC video plus an AAC or
ALAC audio track. This tool drops the picture and rewraps the first audio stream
into an .m4a file with a lossless remux:
ffmpeg -i in.mp4 -vn -map 0:a:0 -c:a copy out.m4a
-vn removes the video stream, -map 0:a:0 selects the first audio track, and
-c:a copy copies the already-compressed audio packets into the M4A container
without running an encoder. There is no quality loss, no bitrate setting, and no
codec conversion. It is the right tool when the audio already fits in M4A and
you want it extracted quickly.
Everything runs locally with ffmpeg in your browser tab. Your video is not uploaded.
Worked example
You recorded meeting.mp4 on a phone and only need the audio. Drop the video on
this page and download meeting.m4a. If the MP4 contains AAC audio, the output
contains the exact same AAC packets, just without the video track. Duration and
quality are preserved; only the container changes.
Limits and edge cases
- Input and output are each capped at 10 MiB.
- The tool extracts the first audio stream (
0:a:0). It does not combine or select among multiple tracks. - It does not transcode. If you need MP3/WAV or a different bitrate, use extract-audio-from-video or audio-convert.
- Videos with no audio track will fail with an ffmpeg "matches no streams" style error.
FAQ
Does MP4 to M4A lose quality?
No. The audio stream is copied with -c:a copy; it is not decoded and encoded
again. The output quality is identical to the audio inside the source MP4.
Why is there no bitrate or quality setting?
Bitrate settings only apply when re-encoding. This tool is deliberately a lossless remux, so it preserves the original audio packets. Use audio-convert if you want to change codec or bitrate.
Which audio track is extracted?
The first audio stream is extracted (-map 0:a:0). If a video contains multiple
language tracks or commentary tracks, this tool does not currently expose a track
selector.
Is my video uploaded?
No. ffmpeg runs inside your browser through WebAssembly. The source video stays on your device.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool mp4-to-m4a 'url=https://example.com/input'New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/mp4-to-m4a/?url=https://example.com/inputMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.