Convert MKV to MP4

Turn an MKV video into an MP4 that phones, TVs and websites accept. It happens in your browser, so nothing is uploaded.

Nothing yet.

Need to make a video smaller instead? Compress a video →

Other formats

What to know

• MKV is a container that can hold many kinds of video. If yours holds H.264 video with AAC sound, it is repackaged as MP4 in seconds.
• If the video is already H.264 with AAC sound, it is copied into an MP4 without re-encoding: quick, and no quality is lost.
• Anything else is converted to H.264 video and AAC sound, which play almost everywhere. That takes longer.
• The picture size and frame rate stay the same.
• It reads MOV, MKV, WebM, MP4 and MPEG-TS files. AVI and WMV are not supported.
• Converting can make the file bigger. To make it smaller, use the compressor afterwards.

Questions

Is my video uploaded?

No. It is converted on your device and never sent to a server.

Why did it take a while?

Videos that are not already H.264 have to be re-encoded, frame by frame. Most phones and computers have video encoding built in, but a long or 4K clip still takes time.

Why is the MP4 bigger than the original?

HEVC, VP9 and AV1 need less data than H.264 for the same picture, so converting to H.264 can make the file bigger. Use the compressor afterwards to bring it down to the size you need.

It says my browser cannot do it.

Use a current Chrome, Edge or Safari. Not every browser can read every video format.