Steven Frady

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Extract Opus Audio from MKV

Free online audio converter. Pull the audio out of MKV video as Opus right in your browser. Files are never uploaded anywhere.

Choose an audio or video file, or drop it here
Output
Other conversions
MP3 → WAVMP3 → AIFFMP3 → FLACMP3 → OGGMP3 → M4AMP3 → OpusWAV → MP3WAV → AIFFWAV → FLACWAV → OGGWAV → M4AWAV → OpusAIFF → MP3AIFF → WAVAIFF → FLACAIFF → OGGAIFF → M4AAIFF → OpusFLAC → MP3FLAC → WAVFLAC → AIFFFLAC → OGGFLAC → M4AFLAC → OpusOGG → MP3OGG → WAVOGG → AIFFOGG → FLACOGG → M4AOGG → OpusM4A → MP3M4A → WAVM4A → AIFFM4A → FLACM4A → OGGM4A → OpusOpus → MP3Opus → WAVOpus → AIFFOpus → FLACOpus → OGGOpus → M4AMP4 → MP3MP4 → WAVMP4 → AIFFMP4 → FLACMP4 → OGGMP4 → M4AMP4 → OpusMOV → MP3MOV → WAVMOV → AIFFMOV → FLACMOV → OGGMOV → M4AMOV → OpusWebM → MP3WebM → WAVWebM → AIFFWebM → FLACWebM → OGGWebM → M4AWebM → OpusMKV → MP3MKV → WAVMKV → AIFFMKV → FLACMKV → OGGMKV → M4A

About MKV and Opus

MKV is the Matroska container — a flexible box that can hold nearly any codec. OBS and most screen recorders write it by default.

Opus is the newest codec here and the most efficient — it outperforms MP3, Vorbis, and AAC at low bitrates, which is why WhatsApp, Discord, and WebRTC all use it. Support is universal in browsers, patchier in older hardware.

Extracting audio from MKV re-encodes only the audio track — the video is discarded, so even long files finish quickly.

How the conversion works

This tool runs FFmpeg — the same engine behind most media software — compiled to WebAssembly, entirely in your browser. Your file is read locally, converted locally, and saved straight from memory; nothing is ever uploaded, which also means no queues and no server-side file size limits.

The converter itself is a one-time ~31 MB download on your first conversion, cached by the browser afterwards. Once it's loaded, everything works offline.

A free tool by Steven Frady, a creative developer building apps, shaders, and interactive installations. See the work.