Upload your .mkv file and get a smaller, optimized MP4. Works with MKV files from any source. Free, no account required.
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Drag & drop your .mkv video file. We support files up to 500MB. No account needed.
SquishVideo converts and compresses your MKV to optimized MP4 H.264, reducing file size while preserving quality.
Get your compressed MP4 instantly. It's compatible with every platform, device, and browser.
MKV (Matroska Video) is an open-source container format that can hold virtually any video codec, audio track, and subtitle stream. It's extremely popular for high-quality video distribution because it supports multiple audio languages, subtitle tracks, and chapter markers in a single file. MKV is the format of choice for video enthusiasts and archivists.
MKV files tend to be large (multiple tracks) compared to optimized MP4. Converting from MKV to MP4 H.264 typically reduces file size by 40-80% while maintaining excellent visual quality. The resulting MP4 also plays on every device and platform without compatibility issues.
MKV was developed by Matroska.org in 2002. It uses the Matroska Multimedia Container container and typically contains Any (H.264/H.265/VP9/AV1) encoded video. Browser support is limited (chrome partial), and mobile support is requires vlc/mx player. For streaming, MKV offers limited capabilities.
Keep MKV if you're doing professional editing and need the original codec quality. Convert to MP4 when: you need to share the video online, upload to social media, send via email, or reduce storage usage. For 99% of sharing and consumption purposes, MP4 is the better format.
| Feature | MKV | MP4 (H.264) |
|---|---|---|
| Container | Matroska Multimedia Container | MPEG-4 Part 14 |
| Typical Codec | Any (H.264/H.265/VP9/AV1) | H.264 / H.265 |
| File Size | Large (multiple tracks) | Optimized (smallest) |
| Browser Support | Limited (Chrome partial) | Universal |
| Mobile Support | Requires VLC/MX Player | Universal |
| Streaming | Limited | Yes, natively |
When you upload a MKV file, SquishVideo first analyzes the video stream to understand its codec, resolution, framerate, and bitrate profile. We then transcode the video to H.264 MP4 using optimized encoding parameters. The entire process preserves audio quality (re-encoded to AAC) and maintains the original resolution unless a lower resolution would provide a better quality-to-size ratio.
MKV files typically come from: video downloads, ripped DVDs/Blu-rays, HandBrake exports, and media servers (Plex/Jellyfin).
SquishVideo supports 20+ video formats. Choose your input format:
Need your MKV video to fit a file size limit? Pick a target: