MKV to MP4 Converter

Convert MKV files to MP4 free in your browser — no signup, no install, and the file is never uploaded to a server. MP4 opens almost anywhere, so the result works where MKV did not.

Completely free Files are never uploaded No signup required
Drop files or click to select
MKV → MP4

What changes in this conversion

  • MP4 uses lossy compression, so some picture detail is discarded permanently in exchange for a much smaller file.
  • MP4 opens almost everywhere, so the converted file will work on devices and programs that refused the original MKV.
  • Both MKV and MP4 are lossy, so re-encoding discards a little more picture detail on top of what was already lost. Converting once is fine; repeating it many times is not.
  • The picture and sound are re-encoded to H.264 video with AAC audio inside the MP4 container, which is what makes the result play on the widest range of devices.

How to use

  1. Add your MKV file

    Drag the MKV file onto the drop area above, or click it to pick a file from your device. You can add several files at once.

  2. Confirm MP4 as the output

    MP4 is already selected as the output format on this page. You can pick the resolution. Encoding is the slowest part, so smaller resolutions finish sooner.

  3. Run the conversion

    Press the convert button. Video is re-encoded frame by frame on your own machine, so a long clip can take several minutes. The tab has to stay open.

  4. Download the MP4 file

    When it finishes, download the MP4 file. Converting multiple files gives you the option to download them together as a ZIP.

About these formats

MKV Matroska Video

An open-source video container able to hold unlimited subtitles, audio tracks, and chapters. It is favored for archiving high-quality video.

Commonly used for High-quality video archives, multilingual subtitled video

MKV File format reference

MP4 MP4 Video

The most widely used video container, playable on virtually every device, platform, and browser. It typically carries H.264 video with AAC audio.

Commonly used for YouTube uploads, smartphone recording, web video

MP4 File format reference

Frequently asked questions

Is converting MKV to MP4 really free?

Yes. MKV to MP4 conversion is completely free with no signup, no watermark, and no daily limit on the free plan for ordinary use.

Are my MKV files uploaded to a server?

No. The conversion runs entirely inside your browser using WebAssembly, so the MKV file never leaves your device. That is also why it works without an internet connection once the page has loaded.

Does converting MKV to MP4 reduce quality?

MP4 uses lossy compression, so some detail is discarded. At high quality settings the difference is usually invisible, and the file becomes far smaller.

Is there a file size limit for MKV to MP4 conversion?

The free plan handles files up to 200MB. Because processing happens on your own device, very large files depend on your computer's memory rather than a server quota.

Convert MKV files to other formats

Convert other formats to MP4

Video converter

What each file format is, what it is used for, and which formats it can be converted to.

Open converter Browse the full format reference