How do I extract audio from an MP4 video online for free?

Drop your MP4 into FileConvertir, select MP3 as output, and download. The audio is extracted and saved as MP3 in your browser — no upload, no account, free.

Is audio quality preserved when extracting from MP4?

If the MP4 audio is AAC (standard for H.264 MP4), it's re-encoded to 192 kbps MP3. Some quality loss is unavoidable (AAC → MP3 is a lossy-to-lossy conversion), but at 192 kbps the difference is inaudible for most content.

Are my videos uploaded to your server?

No. FFmpeg.wasm processes the video entirely in your browser. The video file never leaves your device.

What's the maximum MP4 file size?

100MB per file. A 1-hour lecture at 720p is typically 300–500MB, which exceeds this limit — for large files, use a desktop tool like FFmpeg or HandBrake.

How long does extraction take?

For most MP4 files, audio extraction takes 1–5 seconds per minute of video on a modern computer. The first conversion takes longer because FFmpeg.wasm needs to load.

Can I extract audio from MP4 on my iPhone?

Yes — open FileConvertir in Safari on iPhone, select your MP4 from Files, and download the MP3. Processing happens on your device.

Does the converter work with MP4 files from screen recorders?

Yes. Screen recordings (from Loom, OBS, Camtasia, or the built-in Mac/Windows recorder) in MP4 format are supported.

What if my MP4 has no audio track?

If the MP4 contains no audio (some silent screen recordings don't), the output will be a near-empty MP3. Check that your source video has an audio track before converting.

MP4 to MP3 Converter

Extract audio from MP4 free online — no upload, no signup, 100% private. Convert MP4 video to MP3 in your browser. Works on Windows, Mac, Android. No size tricks.

FileConvertir — Free Online File Converter