Convert Matroska (MKV) to Opus
Free online converter for Matroska (MKV) files. Low-latency codec with excellent quality at low bitrates. Nothing to install, no watermark, and every file is deleted automatically.
Drag and drop your files
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Upload a Matroska (MKV) file to convert it to Opus. Up to 3 files at once, 100 MB each.
Free · up to 3 files · 100 MB each · files deleted automatically after 1 hour.
About MKV and OPUS
Matroska (MKV) .mkv
Matroska: an open container that will hold almost any combination of video, audio, subtitle and chapter tracks in one file.
Good for
- Unlimited tracks — multiple languages, subtitles, chapters
- Codec-agnostic, so it holds nearly anything
- Open, well documented, and resilient to damage
Trade-offs
- Browsers will not play it natively
- Many TVs and phones refuse it — the usual reason to convert
- Being a container, contents vary wildly file to file
video/x-matroska
Opus .opus
The current state of the art in lossy audio, standardised by the IETF. It outperforms MP3 and AAC across the range and is dramatically better at low bitrates.
Good for
- Best quality per byte of any format here
- Excellent for speech as well as music
- Open, royalty-free, and low latency
Trade-offs
- Lossy
- Older devices and some players will not open it
- Less familiar, so people distrust the file extension
audio/opus
MKV and OPUS side by side
| MKV | OPUS | |
|---|---|---|
| Compression | Container — any codec | Lossy |
| Transparency | Depends on codec | n/a |
| Typically used for | Archival video, multi-language releases | Voice, streaming, bandwidth-limited audio |
What changes when you convert MKV to OPUS
Only the sound is kept
This takes the audio track out of the MKV and writes it as OPUS. The picture is discarded entirely, and no conversion back will return it — keep the MKV if you still need the video.
This is a re-encode, not a repackage
Some tools can move a stream into a different container untouched when the codecs happen to line up. We do not — every job here is decoded and encoded again, so the conversion takes time in proportion to the length of the file and costs a small amount of quality even where a repackage would have been possible. In exchange the output is predictable: it plays everywhere, rather than inheriting whatever the source happened to contain.
What your OPUS will contain
The output is Opus — encoded with Vorbis at 192 kbps by default. Vorbis is royalty-free and holds up slightly better than MP3 at the same bitrate, though Opus has largely superseded it for new work.
Other Matroska (MKV) conversions
Other ways to get Opus
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