How to Use the Extract Audio from Video (MP4 to MP3)
- Select the video file you want to extract audio from.
- Wait for the in-browser video engine to load on first use.
- Click Extract to pull out the audio track.
- Download the resulting MP3 file.
Why extract audio from a video
Pulling the audio out of a video is handy when you only need the sound: saving a lecture or interview to listen to later, grabbing a piece of music, keeping a voice note, or turning a talk into a podcast-style file. An MP3 is also far smaller than the video, so it is easier to store and share.
It is a quick way to make video content usable on the go, without a media player or the visual track you do not need.
How it works, and quality
This tool decodes the video and re-encodes just the audio track to MP3, using WebAssembly to run the conversion efficiently on your own device. The first run loads a small processing engine, after which it is quick.
The output can only be as good as the audio in the source; a higher bitrate keeps more detail at the cost of a larger file. Because everything happens in your browser, your video is never uploaded.
Frequently Asked Questions
Is my video uploaded to a server?
No. ffmpeg.wasm processes the video entirely in your browser, so the file never leaves your device.
Why is there a large download on first use?
The tool loads a WebAssembly build of FFmpeg (roughly 25-30 MB) the first time you use it. It's then cached, so later conversions start faster.
What file size works best?
Because processing happens on your device, this works best for files under about 100 MB. Very large videos may be slow or run out of memory, especially on phones.
Which video formats are supported?
Common formats like MP4, MOV, WebM and MKV work for extracting audio.