Pull the audio out of an MKV video as an OPUS. It is converted in your browser, so the file never leaves your device.
Drop MKV files here
or choose from your computer paste with Ctrl V
from Photos or Files
Ready · other file types work too0 bytes uploaded, ever
Drop MKV (Matroska) files onto the box above, or click it to choose them. ToAny reads the file's contents to detect the type, so a wrong extension does not matter.
Press Convert. Open Options first if you want to change the defaults. The work happens in this tab and can take a while for large files.
Save the OPUS, or download everything as one ZIP if you converted several files.
The MKV to OPUS converter is part of this page and runs inside your browser. Your videos are never sent to ToAny or to anyone else.
Nothing has to travel to a server and back, so work starts the moment you press Convert. How long it takes depends on your device and the size of the file.
No sign-up, no email address and no watermark. Add several files and download them together as a ZIP.
MKV does not play on iPhones, in QuickTime or in most browsers and editors. Opus sounds better than MP3 or AAC at low bitrates. MKV is at home in films with several audio and subtitle tracks; OPUS is the usual choice for voice and music at low bitrates. The OPUS contains the soundtrack only; the picture is dropped.
The defaults suit most files. Under Options you can choose the bitrate and trim the start and end. This is demanding work for a browser: a long or high-resolution file can take several minutes, and your device does all of it, so keep the tab open.
The conversion uses your browser's own video and audio codecs (WebCodecs), with hardware acceleration where the device has it; the file is read from disk as it goes and can be up to 2 GB. Where the browser lacks a codec, the page falls back to the compatibility engine. OPUS is written at 128 kbps unless you choose another bitrate.
MKV is an open container that can hold practically any video and audio format plus multiple subtitle tracks. That flexibility is why it is popular for films, and why Apple devices and browsers refuse it.
Opens in VLC, Plex and many TVs; not iPhones, QuickTime or most browsers
MKV converterOpus is a modern open codec that sounds good at very low bitrates. WhatsApp voice notes, Discord and video calls use it. Standalone .opus files are less widely supported than the codec itself.
Opens in Current browsers, Android, VLC; many music apps and hardware players do not
OPUS converter| MKVMatroska video | OPUSOpus audio | |
|---|---|---|
| Stands for | Matroska | Opus |
| Type | Video container | Audio |
| Compression | Depends on what is inside | Lossy |
| Introduced | 2002, by the Matroska project | 2012, by the Internet Engineering Task Force (with Xiph.Org, Mozilla and Skype) |
| Opens in | VLC, Plex and many TVs; not iPhones, QuickTime or most browsers | Current browsers, Android, VLC; many music apps and hardware players do not |
| Best for | Films with several audio and subtitle tracks | Voice and music at low bitrates |
| File extension | .mkv | .opus |
No. The MKV to OPUS conversion runs inside your browser, on your own phone or computer. The file is not sent to ToAny or to anyone else.
The soundtrack is re-encoded as OPUS. OPUS is lossy, but at a normal bitrate the difference is hard to hear. You can choose the bitrate under Options.
Yes. Add as many as you like, convert them together and download each result or all of them as one ZIP.
The steps are the same everywhere because ToAny runs in the web browser: open this page in a current version of Chrome, Edge, Safari or Firefox, add the MKV file, press Convert and save the OPUS. There is nothing to install.
Yes. Files up to 2 GB are accepted. Beyond that the limit is your device's memory, since nothing is uploaded; a computer copes with large files better than a phone.