Free WebM audio (.webm) to MP3 (.mp3) converter running entirely in your browser — with bitrate, sample rate and channel control. No upload, no signup.
MP3 · WAV · M4A · AAC · OGG · Opus · FLAC · WebM · AIFF
A WebM file with no video track is how browsers save recorded audio and how many web downloads arrive. The audio inside is Opus or Vorbis; the container is what confuses desktop players.
Best for: Browser recordings and web downloads; convert for everything else.
MP3 is the format every device on earth can play. Its patents expired in 2017, and while newer codecs compress better at the same bitrate, nothing matches its universal support in cars, DJ gear, hardware players and elderly software.
Best for: Maximum compatibility — cars, old players, anything with an audio jack.
Yes — unlimited, watermark-free and without an account. Conversion runs on your own machine, so there is no per-file cost to pass on.
No. Your browser decodes and re-encodes the audio locally; nothing is transmitted, which matters for voice notes, interviews and unreleased tracks.
Both formats are lossy, so this is a second encoding pass — some quality is lost by definition. Use the highest bitrate you can afford (256–320 kbps) to keep the loss inaudible, or convert to WAV instead if the file will be edited.
Yes. Drop a whole batch — each file is processed in turn and the results can be downloaded individually or together as a ZIP.
WebM audio container tags, chapters and attached artwork are not exposed by the browser audio decoder. The MP3 encoder writes new audio frames without ID3 tags or cover art, so add that metadata afterwards if you need it.