MKV to MP4 converter

To convert MKV to MP4, drop the file here and press Convert to MP4. An MKV from OBS holds H.264 video and AAC sound, which are copied into the MP4 as they are (a remux), so even a long stream converts quickly, loses nothing and keeps every audio track. Free, and nothing is uploaded.

A free tool from Clyper, the AI clipping tool that turns long videos into captioned vertical clips.

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Converted on your device: nothing is uploaded.

Make HEVC (H.265) videos H.264iPhones record HEVC. Copied into MP4 it plays on phones, Macs and most browsers, but some Windows PCs and editors can't open it. H.264 plays everywhere; it's re-encoded, so it takes about as long as the video plays.

Free, no watermark, nothing to sign up for. Copying has no length limit; up to 60 minutes of a video can be re-encoded at a time.

How to convert MKV to MP4

Drop your MKV files in, or choose them: up to 20 at once. Each row says whether it'll be copied (quick, lossless) or re-encoded.
For a file over 1 GB, press Choose where to save it, and convert: the MP4 is written straight to your disk.
Press Convert to MP4 for the rest. A remux of an hour-long recording takes moments, not an hour.
Download each MP4, or all of them at once, and open it in your editor.

MKV and MP4 side by side

MKV and MP4 compared
	MKV	MP4
If the recording is cut off	Stays playable	A regular MP4 may be lost (Hybrid MP4 is safe)
Holds	Almost any video and sound format	H.264, HEVC, AV1; AAC, MP3, Opus
Several audio tracks	Yes	Yes, kept by this converter
Opens in editors and apps	Not always; OBS says it may need remuxing	Everywhere
From OBS, in this converter	Copied into MP4 as it is	Already there

MKV recordings from OBS

OBS recommends MKV because it's failsafe: if the power goes or the disk fills mid-stream, everything recorded up to then still plays. A regular MP4 is only finished when the recording stops, so an interrupted one can be unrecoverable. That's why so many streams and calls end up as MKV files that an editor or a phone won't open.

New OBS profiles record Hybrid MP4 on Windows and Linux (Hybrid MOV on a Mac), which is safe like MKV and opens like MP4. If your recordings are still MKV, your profile is older: switch the format in Settings, Output, Recording, or keep MKV and remux.

Separate audio tracks

In OBS's advanced output you can record your mic, the game and music on their own tracks, for example to leave copyrighted music out of the video you post. An MKV keeps them apart, and so does the MP4 this converter makes: nothing is mixed down. In an editor each track is its own lane; a player plays the first.

Got a stream hours long? Cut it into parts with the video splitter, set OBS up so the next one needs nothing with the best OBS settings for recording, or skip the editing: Clyper takes the MKV as it is and finds the moments worth clipping.

Questions

How do I convert MKV to MP4 without losing quality?

Drop the MKV here and press Convert to MP4. When it holds H.264 or HEVC video with AAC or MP3 sound, as OBS recordings do, the picture and sound are copied into the MP4 untouched. That's called remuxing, and it loses nothing.

Does it keep every audio track?

Yes. If OBS recorded your mic, the game and music on separate tracks, the MP4 has all of them. Most players play the first track; an editor shows each one on its own.

How long does it take?

A remux only rewrites the file, so it's quick even for a stream hours long. Only an MKV with other video (VP9, AV1) is re-encoded, which takes about as long as it plays, up to 60 minutes of video at a time.

My recording is several GB. Will it work?

Yes. Files over 1 GB are written straight to a file you choose as they're made, so they don't have to fit in memory. That needs Chrome or Edge on a computer.

Why did OBS record MKV in the first place?

Because an MKV stays playable if the recording is cut off by a crash or a full disk, where an unfinished regular MP4 may be lost. New OBS profiles record Hybrid MP4, which is just as safe, but older ones often still record MKV.

Can OBS convert MKV to MP4 itself?

Yes: File, then Remux Recordings, or tick Automatically remux to MP4 in the advanced recording settings. This page does the same on a computer without OBS, and for MKVs from anything else.

Sources

Read on November 7, 2026.

Turn the stream into clips

Upload the recording (MKV works as it is) or paste a YouTube or Twitch link. Clyper finds the best moments, frames them vertically and captions every word: up to 30 clips, ready to post.

See plans and pricing