Remux or transcode Matroska video into formats people can actually play.
or choose a file from your device
Remux or transcode Matroska video into formats people can actually play. Justvert keeps this page focused on one format so you can convert into or out of MKV without hunting through a long list of obscure options.
The Strategy Engine still inspects the source. Compatible H.264 streams remux. Hardware-friendly transcodes use WebCodecs. Legacy containers fall back to FFmpeg WASM.
Stay on the same job, or jump to a nearby format change.
A MKV converter changes a media file into or out of the MKV format. On Justvert you drop a file, pick MKV or a related output, and convert in the browser.
The MKV converter accepts common video and audio inputs such as MP4, MOV, WebM, MKV and AVI when the source is a media file. Use Auto detect if you are unsure of the input format.
No. Conversion runs locally in your browser. The chosen file is read on the page, processed by remux, WebCodecs or FFmpeg WASM, then written back with a WritableStream or a download. Source files are not uploaded to a Justvert conversion server.
No. Justvert is an online video converter. Open a modern web browser, drop a file, and convert. There is no desktop app or browser extension to install.
It can, if the file has to be re-encoded. Compatible H.264 plus AAC streams can be remuxed into MP4 without touching the pictures or the sound. WebCodecs and FFmpeg paths re-encode and may introduce some quality loss depending on the source and output size.
MKV is flexible but not universally playable. Remuxing or transcoding to MP4 makes the same video open in more phones and editors.