WebFaz Video Compressor

Reduce an MKV video and convert to MP4

PT

Seu vídeo é comprimido no navegador e não é enviado. Learn more

Reduce an MKV video and convert to MP4

MKV files are usually large and not every device or platform accepts them. Compress the video and download it as MP4 to have a smaller, more compatible file.

Drag your video here or click to choose

MKV

📐 Automatic aspect-ratio detection⚡ 100% private

How to do it, step by step

  1. Select the MKV file.
  2. Choose the compression level and, if you like, the resolution.
  3. Compress (large MKVs may take a while).
  4. Download the MP4.

See where to click, with an image of the tool →

When this is useful

Watch or send on devices without MKV support

MP4 opens on phones, TVs and social networks.

Reduce long recordings

Recording programs often save as MKV at a high size.

Tips for a good result

  • To only change the container without recompressing, the conversion may be faster in another app: see WebFaz Video Converter.

What this tool does not do

  • The compression rewrites the video and has quality losses.
  • Embedded subtitles and extra audio tracks from the MKV are not guaranteed in the new file: check the result.
  • The new file carries the “WebFaz.com” credit in the metadata (comment and artist).

Frequently asked questions

Can I keep MKV as the output?
Yes, the output format can also be MKV, but MP4 is the most compatible.
What about embedded subtitles?
They are not guaranteed in the new file. To work with subtitles, see WebFaz Subtitles.

More Video Compressor tools

Text written by Marcelo Amantino · updated October 18, 2026 · who we are