AnyFormat

00 WebM → MP3

WebM to MP3

For screen recordings and downloaded browser media.

Drop files or a folder here

or choose from your device · paste with ⌘V / Ctrl+V

.webm

03Options 5

Right for speech, wrong for music. At a fixed quality the file size does not change — but mono tolerates a much lower quality than stereo, so combine the two to actually shrink the file.

Leave at 0 for the whole file.

0 means run to the end.

  • No upload The conversion runs in this tab. Your file never travels — not to us, and not to the advertising.
  • No sign-up, no email, no daily cap There is no account system to sign up to.
  • No size limit we invented Only your device's memory — about ~2 GB on a desktop browser, ~400 MB on a phone.
  • Turn your Wi-Fi off and convert anyway The conversion needs nothing but this page. Ads will not load without a connection; your file will still convert. That is the whole claim, and it takes five seconds to check.

Extracts audio from a WebM file as MP3. WebM is what browser-based screen recorders and meeting tools produce, and what a good deal of web media is delivered as.

The audio inside is Opus

WebM restricts itself to royalty-free codecs, so its audio is Opus (or older Vorbis). Opus is an excellent codec — better than MP3 at every bitrate — so converting is a step down in efficiency taken purely for compatibility.

Keep the quality High so the second generation stays inaudible.

Screen and meeting recordings

Browser screen recorders produce WebM, and so do several meeting tools. That audio is speech, usually mono and often already low-bitrate.

Low quality with mono selected is the right setting: it produces a file a fraction of the size that sounds the same, because there was never any stereo information or high-frequency content to preserve.

How MP3 encoding works without a server

Browsers decode MP3 but do not encode it — there is no MP3 encoder in WebCodecs. The encoding here is LAME, the reference open-source MP3 encoder, compiled to WebAssembly and loaded only when you actually convert to MP3.

It is the same encoder desktop software has used for twenty years, producing standard files that play everywhere. Because it is fetched on demand, pages that convert to WAV or M4A never download it.

Other names for this

Also searched as “webm to audio”, “extract audio from webm”.

Questions

What audio codec is in a WebM?
Opus, or Vorbis in older files. Both are read automatically.
Best settings for a meeting recording?
Low quality with mono. Speech has no stereo information to lose, and Low is where the size saving actually comes from.
Is my file uploaded?
No. The demuxing, decoding and encoding all happen in this tab using the browser’s own media stack plus a WebAssembly encoder. A recording can be an interview, a lecture, a private call — none of it is transmitted. Turn your Wi-Fi off after the page loads and it still works.
How large a file can I convert?
There is no imposed limit, only your device’s memory — around 2 GB in a desktop browser and 400 MB on a phone, since the file is held in memory while it converts. A two-hour video converts in well under a minute on a laptop.
Can I convert several files at once?
Yes. Drop as many as you like, or a whole folder. Each keeps its original name with the new extension, and you can download them individually or as a ZIP.