MKV (Matroska) is a flexible container popular for recordings and downloads, but many phones, TVs, editors and websites do not accept it. Converting MKV to H.264 MP4 gives you a video file that plays everywhere.
How to convert MKV to MP4 (H.264)
- Drop your MKV files in the box above, or click to pick them. You can add as many as you like.
- MP4 (H.264) is already selected as the output format. Switch on other formats if you want them too.
- Optional: open Advanced Settings to resize by percentage, width or height, and add more sizes.
- Click Start Conversion, then download each file or all of them at once. Nothing is uploaded: the conversion runs in your browser.
Why convert MKV to MP4 (H.264)?
MP4 with H.264 is the most widely supported video format. The converter decodes the video track of your MKV in the browser and re-encodes it as H.264.
Frequently asked questions
Which MKV files can I convert?
MKV files whose video codec your browser can decode, such as H.264, HEVC, VP8, VP9 or AV1.
Are my videos uploaded?
No. The video is decoded and encoded in your browser, on your device. Nothing is sent to a server, which also means there is no file size limit other than your device memory.
Can I resize the video while converting it?
Yes. Open Advanced Settings and turn on Resize to scale the video by percentage, width or height. You can add more sizes to get several versions in one go.