Convert WebM to MP3 online

If you have a WebM video — the typical format for browser recordings and some web downloads — and you only care about the sound, this converter extracts the audio and saves it as MP3 right in your browser, without uploading the video to any server.

What's extracting the audio from a WebM good for?

WebM is a lightweight format built to play inside the browser, common in screen recordings, recorded video calls, or certain videos embedded on web pages. If all you need from that video is the sound — a recorded meeting, a song, the audio from a livestream — extracting it to MP3 gets you a much lighter file that plays on any phone, car stereo or speaker, without needing the full video.

How it works: a genuine audio re-encode

WebM's audio is usually Opus or Vorbis, codecs MP3 doesn't natively support, so it can't just be copied as-is. We use ffmpeg compiled to WebAssembly, running in your browser tab: it decodes that audio and re-encodes it as MP3 with libmp3lame at a high variable bitrate, without the video ever leaving your machine.

Steps to extract the audio from your WebM

• Choose the WebM file from your device ('Choose file' button).
• Hit 'Convert'. The first time, your browser downloads the conversion engine (a few MB); after that, it's faster.
• Wait for the progress bar to reach 100%.
• Download the resulting MP3 with the 'Download result' button.

An honest note on quality

Re-encoding the audio from Opus/Vorbis to MP3 adds an extra layer of lossy compression on top of whatever the original WebM already had, so the result isn't a bit-for-bit copy. At the high VBR setting we use, that difference is inaudible for voice, podcasts and most music; the final quality mostly comes down to how good the original WebM's audio was to begin with.

Honest limits worth knowing

Since the conversion happens in your browser, the real limit is your device's memory and processing power, not an artificial cap of ours. Very long WebM videos can take longer to re-encode the audio, especially on phones with limited RAM — try a computer if that happens. This converter processes one file at a time, on a single thread.

Other related conversions

If instead you need the full video in a more compatible format, use WebM to MP4 (video and audio re-encoding). And if your file is already in MP4, extract the audio directly with MP4 to MP3. If you don't have the file yet, use our YouTube video downloader.