MKV files are flexible but not universally supported. Converting them to HEVC in an MP4 container keeps file sizes small and makes them play natively on iPhones, iPads, Macs and most modern TVs.
How to convert MKV to HEVC (H.265)
- Drop your MKV files in the box above, or click to pick them. You can add as many as you like.
- HEVC (H.265) 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 HEVC (H.265)?
HEVC is about twice as efficient as H.264, so it is a good choice for long clips. HEVC encoding needs support in your browser and hardware, available in Safari and in Chrome or Edge on many recent devices.
Frequently asked questions
Why does the conversion fail?
Either your browser cannot decode the video codec inside the MKV, or it cannot find an HEVC encoder on this device. Try H.264 MP4, or another browser.
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.