WEBM to MP3
Free online converter
Drop a WEBM (from Loom, OBS, Firefox recording, or a YouTube downloader) and get a clean MP3 in seconds. No watermark, no email.
Drop your .webm file
or click to browse
Max 25 MB · .webm only
How WEBM to MP3 conversion works
Conversion preview
Why use Mictoo for WEBM to MP3?
When WEBM to MP3 is useful
Tips for clean WEBM to MP3
- Video-WEBM is auto-demuxed, no need to strip first.
- For recordings over 25 MB, trim or split the source before uploading.
- The default audio track is used if multiple exist.
- For Whisper transcription, upload the WEBM directly to /webm-to-text.
What happens during conversion
We extract the audio from your WEBM and encode it as MP3.
WEBM vs MP3
| File type | Typical size | Best use |
|---|---|---|
| WEBM | Medium-large | Web recording, browser video |
| MP3 | Small | Sharing, playback, everywhere |
The audio inside WEBM is usually Opus
WEBM is a Matroska container. The audio track is almost always Opus, occasionally Vorbis. Both are more efficient than MP3, which changes the maths of this conversion.
- Opus at 64 kbps
- Roughly comparable to MP3 at 128 kbps
- So the MP3 is often bigger
- You can end up with a larger file that sounds slightly worse
- Where WEBM comes from
- Loom, OBS, browser MediaRecorder, YouTube downloads, Google Meet exports
- How to check
- ffprobe file.webm prints opus or vorbis on the audio stream line
The video track is dropped, not re-encoded
We demux the container, discard video, decode the audio track and encode MP3. Video is never touched, so even a long screen recording converts quickly.
- Typical screen recording
- A 20 MB WEBM often yields a 3 to 4 MB MP3, because most of the size was video
- Speed
- Conversion time tracks audio length, not file size
- Multiple audio tracks
- The default track is used
- Need the video?
- This is the wrong tool. It only ever returns audio
Convert only for compatibility
There is no size or quality argument here, only a support argument.
- Real reasons
- Podcast hosts, older players, DAWs and editors that do not read WEBM or Opus
- Not a reason
- Making the file smaller. Opus already did that better
- Better alternative
- If the target reads Opus, keep the WEBM or remux to .opus losslessly
- Only after text?
- Upload the WEBM straight to our WEBM to text tool
Frequently asked questions
Is the WEBM to MP3 converter free?
Yes. Files up to 25 MB can be converted without an account, and the output has no watermark.
What if my WEBM has video?
We demux the video track server-side and only encode the audio. You do not need to pre-strip anything.
Which WEBM audio codecs work?
Opus (modern, most common) and Vorbis (older). Both are supported directly.
Are uploaded files stored?
No. WEBM is dropped after conversion; the MP3 is purged within the hour.
My WEBM is over 25 MB. What now?
Trim the source before uploading, or extract an audio-only WEBM first to reduce the file size.