WebM to Opus Converter — Free, Online, No Upload

WebM files bundle video and audio together in a single container, and when you only need the audio from a WebM recording — a browser call, a video lecture, a screen capture — carrying the video data is wasteful. Stripping the video and keeping only the Opus audio track gives you a smaller, purpose-built audio file that the browser's audio stack can handle efficiently.

Opus is already the audio codec inside most WebM files, which means converting WebM to Opus often requires nothing more than a remux — extracting the audio stream and placing it in an OGG container without any re-encoding. This preserves the original Opus audio exactly, with no quality loss. The resulting .opus file is the most compact audio format available for the quality it provides.

Opus audio files are natively supported in Chrome, Firefox, and modern Linux media players. They are the native format for Discord, WhatsApp voice messages, and WebRTC systems. If your target is a web app, a communication platform, or an open-source audio pipeline, Opus is the right output. Note that native iOS and older Safari support for Opus is limited — if you need to reach Apple devices, AAC or M4A are better choices. For everything else, this is the most efficient extraction you can do from a WebM file.

Typical sizes: WEBM 50–200 MB (1 minute 1080p); OPUS 1–3 MB (3-minute song).

OPUS output is encoded at 192 kbps.

Re-encoding one lossy format into another adds a second round of compression.