MKV to MP4 converter
Convert MKV to MP4 in your browser. The video and audio streams are copied across rather than re-encoded, so it takes seconds and loses no quality.
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Accepts .mkv · Up to 20 files at a time · up to 667 MB each "Upload" and "download" here mean your browser reading a file from this device and writing one back to it. Nothing is sent to a server — open your browser's network panel and watch: no request carries your file.
FAQ
Will I lose quality converting MKV to MP4?
No, not in the normal case. The video is copied into the new container without being decoded, so it is identical to the source. Quality only changes if you request a different resolution or quality preset, which forces a real re-encode.
What happened to my subtitles?
They were left out, because MP4 cannot carry the SRT and ASS formats MKV uses. This is deliberate: the alternative is a failed conversion. Extract the subtitles from the MKV with a tool like MKVToolNix and keep the .srt next to your MP4 — most players load it automatically.
Are multiple audio tracks kept?
Yes. All audio tracks are carried across, so a file with both an original and a dubbed track keeps both and you can switch between them in your player.
Why does my TV refuse to play MKV in the first place?
MKV is an open container that never became part of the broadcast and mobile standards, so hardware decoders and smart TV firmware often do not implement it. The video inside is usually perfectly ordinary — it is the wrapper they will not open.
Is there a file size limit?
About 667 MB. A container swap produces an output as large as the input, and both need to fit in the memory the converter works in. Films frequently exceed that; for those a desktop tool is the practical answer, since a browser tab cannot hold several gigabytes at once.
Does it work if the MKV holds unusual codecs?
If the video inside is something MP4 does not accept, copying it produces a file that will not play. Turn off "prefer stream copy" in the advanced options to force a genuine re-encode to H.264, which is slower but produces a file that plays anywhere.
Is it really free?
Yes — every conversion on this site, with no account, no watermark and no daily cap. The work happens on your own device, so there is no server bill for us to pass on to you.
Do I need to install anything?
No. It runs in any modern browser, on Windows, macOS, Linux, Android and iOS. There is nothing to download and nothing to sign up for, and once the page has loaded it keeps working with the network switched off.
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