Split Video and Audio (MP3 + MP4)

What does this tool do?

It splits a video into its two parts: the audio as MP3 on one side and the video as MP4 on the other. You pick an MP4, WebM or MOV file and the conversion happens inside your own browser with ffmpeg, so you get two independent downloads without uploading the video anywhere. It is the fastest way to keep just the soundtrack of a recording, or just the picture, without installing a video editor or learning filters, timelines or command lines.

A video is not a single file: inside it carries a video track (the frames) and one or more audio tracks (the sound). Splitting means extracting each track on its own and repackaging it in the format you need. The MP3 output runs at about 190 kbps, more than enough to listen, transcribe or edit voice, and the MP4 is delivered ready to open in any player, phone or social network.

How to use the audio and video splitter

1. Pick the video: drag it into the box or click to browse your device. It accepts MP4, WebM and MOV.
2. The file is checked before converting: the extension, the real content type and its size are verified, so if something does not add up you are told right away.
3. Press “Split audio and video” and you will see the progress. The first time, your browser downloads the conversion engine (about 30 MB) and keeps it for next time.
4. When it finishes, two buttons appear: download the MP3 with the audio and the MP4 with the video.
5. If the video had no audio track, you are told and only the MP4 is delivered; there is no MP3 to extract.

Formats, limits and quality

• Input: MP4, WebM and MOV, up to 200 MB. The real limit is your device’s memory, since the whole file is loaded into the browser to convert it.
• Audio output: MP3 at ~190 kbps, with the original audio decoded and re-encoded only once.
• Video output: MP4 with the index at the front (faststart), so playback starts without downloading the whole file.
• If the video already came as H.264 with AAC audio, the MP4 is built by copying the tracks: it is instant and loses no quality at all.
• If it came in another codec (for example a WebM with VP9 and Opus), it is re-encoded to H.264 + AAC so it opens anywhere. That takes longer the longer the video is.

When splitting audio from video is useful

• Keeping the music or voice of a video to listen to on its own, without carrying the picture.
• Transcribing a class, a meeting or an interview: most transcription tools work better with audio than with video.
• Feeding audio into a voice editor or a subtitling tool without waiting for it to process the whole video.
• Turning something you recorded in WebM or MOV into an MP4, for the places that reject it (social networks, virtual classrooms, forms).
• Recovering just the picture from a screen recording when the audio adds nothing.

What happens to your file

Your video never leaves your device. The conversion is done by ffmpeg compiled to WebAssembly inside your browser: the file is read from your disk, converted in memory and the two results are built as temporary downloads of the browser itself. Nothing is uploaded to any server, no copy is kept, nothing is shared with third parties and no account or email is needed: closing the tab removes it all. The only thing that travels over the internet is the conversion engine (about 30 MB the first time), which the browser keeps for your next visits.

Is my video uploaded to any server?

No. The conversion runs inside your browser: the file is read from your device and never leaves it. There is no upload, no job queue and no temporary copy on a server, which is also why you never wait for a heavy file to upload before it starts working.

Frequently asked questions

Do I lose quality when splitting the audio?

The audio is decoded and re-encoded once to MP3 at ~190 kbps. That rate is meant for listening and for voice work: in a blind test the difference from the original is hard to notice. If you need the audio untouched for a professional mix, it is better to extract it without re-encoding from the original file.

Why does the MP4 sometimes take longer to be ready?

When the video already uses MP4-friendly codecs it is copied as-is and finishes in seconds. When it has to be translated from another codec (VP9, AV1, MPEG-4) it is re-encoded frame by frame, and the time then depends on length, resolution and how powerful your device is, because your own browser does the work: a short clip takes a moment, one of several minutes can take quite a while, and on a phone it shows more. The progress bar tells you where it is and you can cancel whenever you want.

Does it work with hour-long videos?

No. The tool is meant for clips: it accepts up to 200 MB and the whole file is loaded into browser memory. Beyond that, the practical option is a desktop program such as ffmpeg, HandBrake or Shotcut, where the limit is disk space rather than memory.

Does it work on mobile?

It works, with caveats: the phone itself does the conversion, so a long or high-resolution video can take a while and run out of memory. For heavy files it is better to use a computer. The first time, the conversion engine has to be downloaded: about 30 MB.