Matroska to MP4
Convert an MKV Container to Standard MP4
Need to use Matroska to MP4 right now?
A real FFmpeg build compiled to WebAssembly decodes and re-encodes entirely inside your browser.
Drop a video file, or click to browse
Processed locally in your browser — never uploaded
MKV supports far more codecs than most devices actually play — this re-encodes to standard H.264/AAC MP4 for universal compatibility, entirely in your browser.
Features
- Runs entirely in your browser
- Privacy-first — your data is never uploaded
- Real-time, instant results
- 100% free, no sign-up required
- Works on desktop, tablet, and mobile
- No installation needed
Who uses this tool?
People also search for
About Matroska to MP4
MKV (Matroska) is a flexible container format that supports far more codecs, subtitle formats, and multiple audio tracks than most devices actually know how to play — it's popular for archiving and advanced media libraries precisely because of that flexibility, but that same flexibility is exactly what makes MKV files fail to open on phones, smart TVs, and many web platforms. Converting to MP4 trades some of that flexibility for near-universal playability.
A real FFmpeg build compiled to WebAssembly handles the conversion entirely inside your browser, decoding whatever video and audio codecs the source MKV actually uses (which can vary widely, since MKV places no real restriction on codec choice) and re-encoding to standard H.264 video and AAC audio in an MP4 container.
Because MKV files can contain codecs, multiple audio tracks, or subtitle formats that MP4 simply can't hold, this conversion selects the primary video and audio tracks and re-encodes them into the more restrictive but far more compatible MP4 structure — any secondary audio tracks or embedded subtitle streams from the source MKV are not carried over.
The trade-off is straightforward: MKV's extra flexibility for multiple tracks and advanced features is given up in exchange for a file that opens correctly on essentially any device or platform, which is usually exactly the trade a user reaching for this tool wants to make.
How it works
- Upload your MKV file. The file loads into the browser-based FFmpeg engine.
- Conversion runs locally. FFmpeg decodes and re-encodes to H.264/AAC MP4.
- Download the MP4. A widely compatible video file, ready to play anywhere.
Examples
Making an MKV file playable on a phone
Input
movie.mkv with an uncommon codec
Output
an MP4 file that plays on any modern phone