Select the MKV (Matroska) file you want to convert
Click convert - compatible streams are repackaged without quality loss
Preview the result and download your MP4 file instantly!
Converting MKV videos to MP4 has never been this easy, free, and secure!
Fublix's MKV to MP4 converter is 100% free and has no limits! Use it as many times as you want without paying anything.
No files are uploaded or sent to any server. The entire conversion takes place locally in your browser. 100% safe and secure.
No limit on the number of files you can convert. Convert as many files as you need, whenever you need.
MKV (Matroska) is beloved for high-quality video storage because it can hold almost any codec, multiple audio tracks, and subtitles. The downside: many phones, smart TVs, browsers, and editing apps simply refuse to open it.
MP4 is the universal alternative. Since MKV files typically carry H.264/H.265 video and AAC/AC3 audio, conversion is often just a matter of repackaging the same streams into an MP4 container - which our tool does without re-encoding whenever possible, preserving every bit of the original quality.
The conversion runs entirely in your browser, so even large MKV files convert quickly with no upload wait.
Fublix never uploads your video. The MKV to MP4 conversion is performed locally in your browser, powered by WebCodecs and hardware acceleration.
Free, unlimited, no watermarks, and completely private.
