Convert MKV to MP4 Free — Online MKV Converter

MKV (Matroska Video) is a powerful container format that supports multiple audio tracks, subtitles, and chapter markers. But its biggest weakness is compatibility. With 38,000 monthly searches for "mkv to mp4," tens of thousands of people hit this compatibility wall every month.

MiOffice converts MKV to MP4 directly in your browser using FFmpeg WebAssembly. No file upload to any server, no software installation, no signup.

How to Convert MKV to MP4

1. 1

   Open the MKV to MP4 Converter

   Go to the MKV to MP4 converter.

2. 2

   Select Your MKV Files

   Drag and drop your MKV file(s). Choose quality: High, Medium, or Low.

3. 3

   Download MP4

   Click convert. Your MP4 files are ready -- compatible with every device and platform.

MKV vs MP4: Compatibility Comparison

When to Keep MKV

MKV excels at storing high-quality video with multiple audio tracks and subtitle streams. If you watch videos exclusively on a PC with VLC or a media server like Plex, MKV is fine. Convert to MP4 when you need to play on mobile devices, upload to social media, embed on websites, or share with others.

Need to Save Subtitles First?

MKV files often contain embedded subtitle tracks that are lost during conversion. If your MKV has subtitles you want to keep, use the subtitle extractor first to save them as SRT files, then convert the video to MP4.

Privacy

MiOffice processes your MKV files locally using FFmpeg WebAssembly. No file is uploaded to any server. The conversion runs entirely in your browser tab.