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Convert Video to MP3 Without Uploading

Pull the audio out of an MP4, MOV, WebM or MKV and save it as an MP3. The conversion happens in your browser and the video is never uploaded.

Runs entirely in your browser — nothing is uploaded

Why this one does not upload anything

Every other converter for this job works the same way: you send the video to a server, it does the work, you download the result. That design is why they all cap the file size, queue you behind other people at busy times, and ask you to wait out an upload before the conversion has even started.

This one runs ffmpeg compiled to WebAssembly inside your browser. The video is read from your disk and decoded on your own machine. Nothing crosses the network, which removes the upload wait, removes the size cap, and means a video you would rather not hand to a stranger simply never leaves.

Choosing a bitrate

The bitrate decides how many bits each second of audio is allowed. More bits means more detail retained and a larger file, and the useful range is narrower than the options suggest.

  • 192 kbps is the sensible default. Most listeners cannot tell it from the source on ordinary equipment.
  • 320 kbps is worth it only when the source is genuinely high quality and the destination is a good pair of headphones.
  • 96 to 128 kbps is right for speech. A lecture, an interview or a podcast sounds the same and takes a third of the room.

One thing no setting can do is improve on the source. The audio inside a video has already been compressed once, and converting it to MP3 compresses it again. Asking for 320 kbps from a video whose own audio was 128 does not restore anything — it just stores the same sound less efficiently.

What affects how long it takes

The first conversion in a session downloads the 31 MB engine, which is the bulk of the wait on a slow connection. It then stays in memory, so anything you convert afterwards starts immediately.

After that, the work scales with the length of the audio rather than the size of the video, because the picture is discarded rather than decoded. A two-hour recording takes a while; a three-minute clip is quick, even if the file it came out of was large.

Formats it will take

MP4, MOV, MKV, WebM, AVI and M4V all work, along with most things a phone or a screen recorder produces. If a file is refused it is usually because it is not really a video — a download that failed part way through is the common case, and it will not open in a player either.

Frequently asked questions

What bitrate does it produce?

192 kbps by default, which is transparent enough for speech and close to it for music. You can choose a lower rate for a smaller file where the source does not justify the bits — a recorded lecture or a podcast sounds the same at 96.

Can it sound better than the original?

No, and no tool can. The audio inside a video has already been compressed once; converting it to MP3 compresses it a second time. Choosing a very high bitrate does not recover what the first pass discarded, it only makes a larger file. Matching roughly what the source used is the sensible setting.

Does this work on a video I downloaded?

It works on any video file already on your device, whatever its origin. It cannot fetch a video from a URL — this is a converter, not a downloader — and whether you may extract audio from a particular file is a question about that file's licence rather than about the tool.

Is the video uploaded to convert it?

No. The decoder runs inside your browser, so the file is read from your disk and worked on in memory on your own machine. You can confirm it: open your browser's network tab and run a conversion, and no request carries the video anywhere.

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