MP4 to MKV Converter
Convert MP4 to MKV online for free. Change video format for playback, editing, uploads, social sharing, or better compatibility across devices and platforms.
Converting MP4 to MKV re-encodes the video into the MKV container. Resolution and frame rate are preserved by default, and the audio track is copied without re-encoding when codec compatibility allows. File size depends on the chosen output codec.
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Checking files and selected output formats.
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Convert MP4 Video in 3 Steps
Re-encode a video for broader playback support, easier editing, smaller files, or platform-specific upload requirements.
Drop your MP4 video onto the tool or click to browse. Our converter handles all major codecs including H.264, H.265, VP8, and VP9 inside the MP4 container.
Your video is re-encoded into the MKV container with the optimal codec. Resolution and frame rate are maintained, and the audio track is preserved without re-encoding when possible.
Download your converted MKV video ready for playback, editing, or uploading to any platform. Files are automatically deleted from our servers within 24 hours.
Why Convert MP4 to MKV
MKV can hold virtually unlimited audio, subtitle, and video tracks in a single file. Store a movie with dozens of language audio tracks and subtitles in one convenient container.
MKV supports every major video codec including H.264, H.265, VP9, AV1, and more. It is the most flexible container format, accepting virtually any combination of audio and video codecs.
MKV files support embedded chapters with named markers, allowing viewers to jump between scenes, segments, or episodes. Chapter metadata makes long videos easy to navigate.
MKV can store lossless video codecs like FFV1 and lossless audio like FLAC, making it the preferred format for archiving high-value video content without any quality loss.
MKV containers can embed fonts, cover art, and supplementary files directly inside the video file. Styled subtitles display correctly everywhere because the required fonts travel with the file.
MP4 vs MKV: Side-by-side
Technical comparison of the two formats — useful for deciding which to use, or for confirming what changes during conversion.
| Property | MP4 | MKV |
|---|---|---|
| Full name | MPEG-4 Part 14 | Matroska Video |
| Year introduced | 2001 | 2002 |
| Developer / standard body | MPEG | Matroska Foundation |
| MIME type | video/mp4 | video/x-matroska |
| File extension | .mp4 / .m4v | .mkv |
| Compression | H.264 or H.265 codec | Codec-flexible (H.264, H.265, AV1, VP9) |
| Color / data depth | 8/10-bit | Up to 12-bit |
| Max dimensions / size | Codec-dependent (up to 8K) | Codec-dependent |
| Transparency | No | No |
| Animation | No | No |
| Standard / specification | ISO/IEC 14496-14 | Matroska |
| Best for | Universal video compatibility — plays on every device | High-quality video with multiple audio/subtitle tracks |
About the MP4 Format
MP4 (MPEG-4 Part 14) is an ISO standard multimedia container format based on Apple's QuickTime file structure. It is the most widely supported video format in the world — capable of playing on virtually every device, browser, and platform without additional software. MP4 files typically contain H.264 or H.265 video streams paired with AAC audio, though the container can hold a variety of codec combinations.
MP4 is the default choice for video distribution across the web, social media, streaming platforms, and mobile devices. Its combination of broad compatibility, efficient compression, and reasonable quality makes it suitable for everything from casual smartphone recordings to professional video delivery. The main limitations of MP4 are its relatively basic subtitle support compared to MKV, and the fact that some advanced codec configurations may not be universally playable on older devices.
MP4 to MKV FAQ
Quick answers about compatibility, quality, metadata handling, and the most common reasons to convert MP4 files to MKV.
How do I convert MP4 to MKV online?
Why would I convert MP4 to MKV?
Will converting MP4 to MKV affect video quality?
How will file size change when converting MP4 to MKV?
When is MKV a better target than MP4?
Can I batch convert multiple MP4 files to MKV?
Is it safe to convert MP4 to MKV online?
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