Convert MP4 to MKV Online Free
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About MKV
MKV (Matroska Video) is an open, flexible video container format that can hold high-quality video, audio, subtitles, and chapters in a single file. It is widely used for archiving, ripping, and sharing media because it supports modern codecs without locking you into one ecosystem.
MKV files often play best in dedicated media players like VLC. Converting MKV to MP4 or MOV is a common step when you need smoother playback on phones, tablets, or Apple devices.
Fun fact: The Matroska project began in 2002 and is named after Russian nesting dolls, reflecting its ability to hold many types of media in one file.
Why Convert MP4 to MKV?
Converting MP4 to MKV moves your video into a flexible open container that can hold multiple audio tracks, subtitles, and chapters in one file. MKV is a popular choice for archiving and media libraries.
MKV is less universally supported than MP4 on phones and built-in players, so choose MKV when flexibility and preservation matter more than instant compatibility.
How to Convert MP4 to MKV
Select your MP4 files, open Settings to adjust quality if needed, and click Convert. Your MKV download will be ready in seconds.
Frequently Asked Questions
Is this MP4 to MKV converter free?
Yes, our MP4 to MKV converter is completely free to use with no watermarks.
Are my MP4 & MKV files safe?
Yes. Files are processed entirely in your browser. They are not uploaded or stored on our servers.
Does this work on mobile?
Yes, you can convert MP4 to MKV directly from iPhone, Android, or desktop browsers.