MKV Compressor
Compress Matroska video into a smaller, widely supported MP4.
Drop a MKV file to compress
Output: MP4 · re-encoded in your browser (first use loads the media engine)
No server upload — processed on your device
Computer · URL · cloud · drag & drop
How to use this tool
Add a MKV file
This page accepts MKV. Max 100 MB — processing stays in your browser.
Tune compression
Lower quality for a smaller MP4. First use may load the local media engine.
Download MP4
Save the compressed MP4 locally when you are happy with the size.
Frequently Asked Questions
More on quality loss: conversion quality guides · compression guides
Is the mkv compressor free?
Yes. Format Convertly compresses files in your browser with no signup.
Do you upload my files?
No. Encoding stays on your device.
What does MKV Compressor output?
Output is MP4.
Need a different format?
Open the MKV format hub for converters, comparisons, and related tools.
Does compressing video reduce quality?
Re-encoding can. Higher quality settings keep more detail at larger sizes. Keep the camera/NLE master when possible.
What is generational loss for video?
Damage from repeatedly re-encoding the same clip. Compress once from the best master for delivery.
How does video compression work?
Compressors re-encode frames (usually to MP4). Lower quality/bitrate shrinks files. See How video compression works and How bitrate affects file size.
Why did my compressed video look softer?
Lossy re-encoding discards detail for size. Raise the quality setting or start from a better master — explained in Why compressed files lose quality.
Where can I learn more about compression?
Browse Format Convertly’s Compression guides — what compression is, lossy vs lossless, image/video/audio how-tos, bitrate, and PDF size tips — each links back to the matching compressor.
Ready to convert more formats?
Browse converters or jump back to the tool above.