MKV TO MP4 AND MORE
Convert MKV to MP4, or any other video format.
The most common job here is MKV to MP4, and it usually finishes in seconds. The same tool also handles MOV, WEBM, AVI and animated GIF, and can pull the audio out on its own as MP3 or WAV. Nothing is uploaded, the conversion runs on your own device.
Drop a video here, or browse
MKV, MP4, MOV, AVI, WEBM and more. Nothing is uploaded
When the video already uses a format the target container accepts, it is repackaged rather than re encoded and finishes in seconds.
Getting ready
An MKV to MP4 converter that keeps the file on your computer
Almost every free video converter online works the same way. You upload your video, it is converted on their servers, and you trust that it was deleted afterwards. For a clip from a phone that might be fine. For anything personal, or anything belonging to a client, it means handing a private file to a company you know nothing about, and waiting on an upload before the work even starts.
This one does the conversion on your own machine. There is no upload, no queue and no account, and the practical limit is your own hardware rather than a free tier.
MKV to MP4 is usually instant
A video file has two parts worth separating in your head. There is the container, which is the wrapper, and that is what MKV, MP4, MOV and AVI actually are. Then there is the video itself inside it, which is usually encoded in a format called H.264.
Most MKV files hold H.264 video, and MP4 accepts H.264 quite happily. So converting MKV to MP4 often means nothing more than putting the same video into a different wrapper. The tool checks for this and takes that path when it can, which finishes in seconds and loses no quality, because the video is never touched. Only when the formats genuinely disagree does it fall back to a full conversion.
What it is good at, and what it is not
Being clear about this saves you a wasted hour.
It suits changing containers, short clips, phone videos, screen recordings, pulling audio out of a video, and making a GIF from a few seconds of footage.
It does not suit long films, large archives, or batch work across dozens of files. A browser tab has a memory ceiling and a speed penalty, and no amount of clever code removes either. If you convert big videos regularly, a desktop program is the right tool and this is not trying to replace it.
Formats
Video can go out as MP4, MKV, MOV, WEBM or AVI, or as an animated GIF. Audio can be pulled out on its own as MP3 or WAV. Most common formats are accepted going in, including MKV, MP4, MOV, AVI, WEBM, FLV, WMV and MPEG.
Once you have the file, the photo to PDF converter and the image converter handle the still image side of things if you need it.
For a walkthrough with a real example, see the blog guide on converting MKV files to MP4 for free, or the shorter how to convert MKV to MP4 guide.
How do I convert MKV to MP4?
Drop the MKV file onto the tool above, choose MP4 as the format and press convert. Most MKV files already hold video that MP4 accepts, so the file is simply repackaged rather than re encoded, which takes seconds and loses no quality at all.
Is my video uploaded to a server?
No. The whole conversion runs inside your browser on your own device. Nothing is sent anywhere, which is unusual for a video converter and is the reason there is no file size charge or queue.
Why is it slow?
Because a browser tab is doing work that a desktop program does with far more access to your machine. Repackaging is quick. Re encoding a long video takes real time, sometimes several times the length of the video itself. Short clips are where this tool is comfortable.
Why is there a wait the first time?
The converter is a complete video engine that has to be downloaded before anything can happen. It is a large file. Once it has loaded it stays cached, so the next conversion in the same session starts straight away.
What size of video can it handle?
That depends on how much memory your browser can spare. Clips of a few hundred megabytes are usually fine on a normal computer. Very large files can run the tab out of memory, and there is no way around that limit from inside a browser.
Can I pull the audio out of a video?
Yes. Choose MP3 or WAV as the format and only the audio track is written out, which is much faster than a video conversion.
Does converting reduce quality?
Repackaging does not touch the video at all, so quality is identical. Re encoding always loses a little, and the quality setting controls how much. High keeps more detail in a bigger file, small does the opposite.