Convert MKV to Opus
Choose your MKV file and get a Opus file in seconds. Nothing leaves your device.
Converter
- FilesOne or many, images and videos mixed
- FolderEvery matching file inside, subfolders included
- ArchiveZIP, RAR, 7z or TAR: convert the contents or the archive itself
Drop files, folders or archives here
Unsupported files are skipped. Nothing is uploaded.
Everything runs in your browser. Files are not uploaded.
About this conversion
The sound track is taken out of the MKV video, handy for music, podcasts, lectures and interviews.
Good to know
Only the sound is kept and the picture is dropped. With several audio tracks, the first one is used.
Opus always works at 48 kHz, so the sound is resampled.
How it works
The audio is converted by ffmpeg compiled to WebAssembly. It loads only when you choose a file and runs in a background thread.
Your browser can
- Built-in image codecs
- Hardware video (WebCodecs)
- Multiple threads
- Create AVIF natively
If something is missing, the conversion takes a little longer but still works.
About MKV (Matroska Video)
MKV is a flexible open container that holds any number of video, audio and subtitle tracks.
- Movie archives
- Videos with several languages
- Screen recordings (OBS)
About Opus (in an Ogg container)
Opus is the most efficient modern audio codec, used by WhatsApp voice messages, Discord, WebRTC and YouTube.
- Excellent quality at very low bitrates
- Great for speech and music alike
- Open and royalty free
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Frequently asked questions
Are my files uploaded to a server?
No. The conversion runs entirely in your browser with local code. Your files never leave your device, and there is no upload.
Is there a file size limit?
There is no limit on our side, but your browser memory is. Images work for very large files; for videos, files above a few hundred megabytes can fail on devices with little memory.
Will the quality suffer?
That depends on the target format and settings. Use the quality option to balance size and detail; lossless targets keep everything the source contained.
Which browsers are supported?
Current versions of Chrome, Edge, Firefox and Safari. Fast hardware paths are used where available, with a compatible fallback otherwise.