MKV to MP4 Converter

Remux or convert MKV videos to MP4 — 100% free, forever. No subscriptions, no credits, no file size limits, no sign-up required.
🔒 100% Offline ⚡ Runs in Your Browser ♾ Unlimited Conversions 🚫 No Account Needed
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Drop MKV Videos Here

Select or drop one or more .mkv files — converted locally, never uploaded

🔄 Need to do the exact opposite? Try our MP4 to MKV Converter

Free MKV to MP4 Converter — 100% Private & Offline

This MKV to MP4 converter runs entirely inside your browser using WebAssembly. Your video files are never uploaded to any server — all processing happens locally on your device. Your files stay completely private, even without an internet connection after the page loads.

Completely free, no strings attached. There are no subscription plans, no credit systems, no watermarks, no file size caps, and no daily conversion limits. Convert as many MKV videos as you want, as many times as you want — for free, forever.

Why convert MKV to MP4? MKV is a flexible container that supports many codecs, but MP4 is the universal standard supported by every device, TV, phone, and video editor. Converting to MP4 ensures your files play anywhere without compatibility issues.

Fast remux or full re-encode. Use "Copy Stream" for an instant, lossless container change that preserves 100% of the original quality. Or choose "Re-encode to AAC" for maximum compatibility with players that don’t support the original audio codec.

Your privacy is guaranteed by design. Because conversion happens entirely offline in your browser, there is no risk of your videos being stored, analyzed, or shared. No account, no email, no tracking — just open the page and convert.

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Frequently Asked Questions

What does 'remuxing' mean compared to converting? +
Remuxing (multiplexing) simply extracts the video and audio streams from the MKV container and places them into an MP4 container. It does not alter the actual video data, making the process blazing fast with zero loss in quality.
Why do some MKV files fail to remux to MP4? +
The MP4 format only supports specific video codecs (like H.264/H.265) and audio codecs (like AAC). If your MKV contains an unsupported codec (like FLAC audio or VP9 video), it cannot be remuxed and must undergo a full, slower conversion.
Is the remuxing done offline? +
Yes! The tool uses local browser technologies to parse and repackage the video container. Even massive 10GB MKV movies can be remuxed locally without uploading them to a server.