Convert MP4 to MKV free, right in your browser - your file never gets uploaded.
Drop files here or click to browse · video, audio, or images · convert several at once
EasyConvert turns MP4 files (the most widely supported video format - it plays on phones, TVs, browsers, and editing software) into MKV (a flexible container popular for HD movies and TV rips, but not supported by many players and editors). Unlike traditional online converters, nothing is uploaded to a server: the conversion runs on your own device using WebAssembly. That means no waiting for uploads, no privacy worries, and it works even on large files.
Drop your MP4 file in the box above, choose MKV as the output format, and click Convert. When it finishes, click Download. Nothing is installed and nothing is uploaded.
Yes. The converter runs entirely in your browser using WebAssembly (ffmpeg.wasm). Your file never leaves your computer - we could not see it even if we wanted to.
Yes - up to 5 conversions per day with files up to 1 GB. EasyConvert Pro ($5/month) removes both limits.