How do I compress an MKV file?

Drop the MKV onto the compressor above, keep Balanced or pick another level, and click Compress. Download the smaller MKV when it's done; it usually takes a few seconds.

Does compressing MKV reduce quality?

A little, by design: MKV is a lossy format. Balanced is tuned to look the same for most uses; choose Light if you want to stay closer to the original.

How much smaller will my MKV get?

High-bitrate MKV recordings shrink a lot; MKVs that were already encoded efficiently shrink less.

Can I compress MKV to a specific size?

Yes. Set a target size in the compressor, or a percentage to reduce by, and the file is compressed to land at or just under it.

Is it safe to compress MKV files here?

Yes. MKV files are compressed inside your browser with WebAssembly and never uploaded to a server.

Is the MKV compressor free?

Yes. Compression is free with no watermark and no sign-up, within the same daily allowance as conversions.

Should I convert my MKV instead?

Sometimes. MP4 plays on phones, TVs and in every browser. The MKV to MP4 converter does that in one step.

MKV→smaller MKV→MP4 JPG→smaller MKV→MP3 PNG→smaller MKV→WebP MP4→smaller MKV→MOV MP3→smaller MKV→GIF PDF→smaller MKV→WAV WebP→smaller MKV→WebM HEIC→smaller MKV→M4A DOCX→smaller MKV→AVI GIF→smaller MKV→FLAC SVG→smaller MKV→AAC MOV→smaller MKV→OGG AVIF→smaller MKV→WMV MKV→Opus M4A→smaller MKV→M4V MKV→FLV WebM→smaller MKV→MPEG MKV→3GP XLSX→smaller MKV→WMA MKV→TS EPUB→smaller MKV→MPG MKV→AIFF AVI→smaller MKV→AMR MKV→VOB FLAC→smaller PNG→JPG JPG→PNG PPTX→smaller PNG→WebP JPG→WebP AAC→smaller WebP→PNG WebP→JPG ZIP→smaller HEIC→PNG HEIC→JPG TIFF→smaller MP4→MP3 PNG→JPEG OGG→smaller JPG→JPEG JPEG→PNG Opus→smaller JPEG→JPG PNG→PDF 7Z→smaller JPG→PDF PDF→PNG ODT→smaller PDF→JPG HEIC→WebP TAR.GZ→smaller MP4→WebP PDF→DOCX ODS→smaller DOCX→PDF JPEG→WebP ODP→smaller WebP→JPEG PNG→GIF TAR.BZ2→smaller JPG→GIF GIF→PNG TAR.XZ→smaller GIF→JPG MP4→MOV MOV→MP4 WebP→PDF HEIC→JPEG WebP→GIF GIF→WebP HEIC→PDF MP3→WAV WAV→MP3 JPEG→PDF PDF→JPEG SVG→PNG SVG→JPG HEIC→GIF MOV→MP3 MP4→GIF GIF→MP4 JPEG→GIF GIF→JPEG PNG→AVIF JPG→AVIF AVIF→PNG AVIF→JPG MP3→M4A M4A→MP3 GIF→PDF SVG→PDF PNG→SVG JPG→SVG PDF→SVG SVG→WebP MOV→WebP MP4→WAV MP4→WebM WebM→MP4 WebP→AVIF AVIF→WebP WebP→SVG SVG→JPEG MP4→MKV HEIC→AVIF MP4→M4A JPEG→AVIF AVIF→JPEG JPEG→SVG MOV→GIF GIF→MOV WebM→MP3 AVIF→PDF MP3→FLAC FLAC→MP3 MP4→AVI AVI→MP4 GIF→AVIF AVIF→GIF SVG→GIF GIF→SVG WebM→WebP MOV→WAV XLSX→PDF CSV→PDF EPUB→PDF PDF→EPUB MOV→WebM WebM→MOV PNG→ICO JPG→ICO ICO→PNG ICO→JPG MP3→AAC WAV→M4A AAC→MP3 M4A→WAV MP4→FLAC AVI→MP3 MOV→MKV MOV→M4A

Compress MKV

Make MKV files smaller without visible quality loss. Free and private: compressed in your browser on computers; on phones, in our fast cloud and deleted automatically.

In your browser (fast cloud on phones)
Same format, smaller file
Batch & ZIP download

How to compress MKV

1
Add your MKV files
Drag and drop MKV files onto the compressor, paste them, or click to browse. You can add several at once.
2
Pick a level or a target
Balanced is selected and suits most files. Choose Light to stay closer to the original or Strong for the smallest file, or set a target size or a percentage to reduce by.
3
Compress
Click Compress. Your MKV files are processed right in your browser, usually in seconds.
4
Download
Download each smaller MKV, or everything at once as a ZIP.

What compression does to MKV

LossyIn your browser

Re-encodes the video at a lower bitrate (and resolution on Strong).

Light: Near-lossless: re-encodes conservatively and keeps the full resolution.
BalancedDefault: The default: looks the same for most uses, and typically 40–70% smaller.
Strong: Smallest file: lower quality, and large videos are downscaled.

Need it much smaller? MP4 plays on phones, TVs and in every browser. Convert MKV to MP4

Need an exact size?

Set a target size in the compressor above, or a percentage to reduce by, and each MKV is compressed to land at or just under it. These pages preset the most common video sizes and take MKV too:

MKV · Matroska Video

MKV is a flexible open container that can hold unlimited video, audio and subtitle tracks in nearly any codec.

Type: Video
Extension: .mkv
MIME: video/x-matroska
Best for: movies and series with multiple audio and subtitle tracks

Open standard

All MKV conversions →

Compress other videos

All videos →

Compressing MKV: frequently asked questions

Free, private and in your browser

Smaller MKV files, in seconds.

No sign-up, no watermark, no upload. Drop a file and get it back lighter.

Compress a file All compress tools

Most conversions never leave your device
Cloud files deleted automatically
No watermarks