Your Complete Video Toolbox

Wondershare UniConverter

  • Compress MKV files to MP4 and other 1000+ video formats.
  • Reduce MKV video size by changing bit rate, video resolution, quality, and others.
  • Edit MKV videos before compressing with trimming, cropping, rotating, adding watermarks, etc.
  • Support batch conversion and compression process.
  • Versatile toolbox combines DVD Burn, Screen Recorder, GIF Maker, Fix Video Metadata, etc.
compress MKV videos


1. Play MKV on Device+
  1. 1.1 Top MKV Player
  2. 1.2 Play MKV on Mac
  3. 1.3 Play MKV on Apple TV
  4. 1.4 Play MKV on Samsung TV
  5. 1.5 Play MKV on Sony TV
  6. 1.6 Play MKV on LG TV
  7. 1.7 Play MKV on PS3
  8. 1.8 Play MKV on Xbox One
  9. 1.9 Play MKV on Xbox360
  10. 1.10 Play MKV to iPhone
  11. 1.11 Play MKV to iPad
  12. 1.12 Play MKV on iPod
  13. 1.13 Play MKV on Android Phone
  14. 1.14 Play MKV in VLC
  15. 1.15 Play MKV in Windows Media Player
  16. 1.16 MKV Playback Issues in VLC
2. Convert MKV to Other Format+
  1. 2.1 Convert MKV to MP4
  2. 2.2 Convert MKV to MP4 on Mac
  3. 2.3 Convert MKV to MP4 Online
  4. 2.4 Convert MKV to MP3
  5. 2.5 Convert MKV to Audio
  6. 2.6 Convert MKV to WMV
  7. 2.7 Convert MKV to M4V
  8. 2.8 Convert MKV to AVI
  9. 2.9 Convert MKV to AVI Online
  10. 2.10 Convert MKV to FLV
  11. 2.11 Convert MKV to DVD
  12. 2.12 Convert MKV to MOV
  13. 2.13 Convert MKV to iTunes
  14. 2.14 MKV to MOV Converter Online
  15. 2.15 Convert MKV to VOB
  16. 2.16 Convert MKV to DivX
  17. 2.17 Convert MKV to MPEG
  18. 2.18 Convert MKV to MPEG2
  19. 2.19 Convert MKV to MPEG4
  20. 2.20 Convert MKV to XviD
  21. 2.21 Convert MKV to 3GP
  22. 2.22 Convert MKV to M2TS
  23. 2.23 Convert MKV to H264
  24. 2.24 Convert MKV to TS
  25. 2.25 Convert MKV to VCD
  26. 2.26 Convert MKV to AC3
  27. 2.27 Burn MKV to DVD
  28. 2.28 Burn MKV to Blu-ray
  29. 2.29 Convert MKV to SWF
  30. 2.30 Convert MKV to MP4 with Subtitle
  31. 2.31 Convert MKV to WAV
  32. 2.32 Convert MKV to MPG
  33. 2.33 Convert MKV to ISO
3. Convert Other Format to MKV+
  1. 3.1 Convert MP4 to MKV
  2. 3.2 Convert MP4 to MKV on Mac
  3. 3.3 Convert MP4 to MKV Online
  4. 3.4 Convert M4V to MKV
  5. 3.5 Convert WMV to MKV
  6. 3.6 Convert MOV to MKV
  7. 3.7 Convert DVD to MKV
  8. 3.8 Convert M2TS to MKV
  9. 3.9 Convert AVI to MKV
  10. 3.10 Convert Bluray to MKV
  11. 3.11 Convert FLV to MKV
  12. 3.12 Convert AVCHD to MKV
  13. 3.13 Convert OGM to MKV
  14. 3.14 Convert MTS to MKV
  15. 3.15 Convert WTV to MKV
  16. 3.16 Convert VOB to MKV
  17. 3.17 Convert RMVB to MKV
  18. 3.18 YouTube to MKV
  19. 3.19 Convert WebM to MKV
4. Edit MKV & Other Tips+
  1. 4.1 Extract Subtitles from MKV
  2. 4.2 Add Substitles to MKV
  3. 4.3 Add SRT to MKV
  4. 4.4 Compress MKV Video
  5. 4.5 Reduce MKV File Size
  6. 4.6 Cut MKV Files
  7. 4.7 Edit MKV Metadata
  8. 4.8 MKV No Sound
  9. 4.9 MKV Video Player for Android
  10. 4.10 MKV Converter for Mac
  11. 4.11 Free MKV Converter
  12. 4.12 MKV Player Mac
  13. 4.13 2D to 3D MKV Converter
  14. 4.14 Remux MKV
  15. 4.15 MKV Encoder
  16. 4.16 Convert MKV to FCP Mac
  17. 4.17 Stream MKV to TV with Chromecast
  18. 4.18 Import MKV to iMovie
  19. 4.19 Windows DVD Maker MKV
  20. 4.20 Convert MKV to MP4 with HandBrake Alternative

Best MKV Video Compressor: How to Compress MKV Files without Quality Loss

by Christine Smith • 2020-09-21 16:02:29 • Proven solutions

Nowadays, movies or TV shows streamed over the Internet are increasingly seen in MKV extensions, particularly for high-definition sources (1080p). But its flat body may cause trouble when viewing it back. Maybe your old CPU is impossible to watch such HD 1080p movies/videos. Or your portable gadget like HTC, Samsung Galaxy, etc. has limited space to store them. Normally, you'll try some MKV video compressors for emails or pictures like 7-zip, Xarchiver, WinRAR, WinZip, etc. However, the MKV file format is already highly compressed and will not benefit from further compression. What to do?

Professional video compressor tools can help you compress MKV videos further. In this article, you'll find the best MKV compressor and other free online solutions to compress MKV videos easily and quickly.

Part 1. How to Compress MKV Files Without Losing Quality on Windows/Mac

Actually, all you need is this stylish and intuitive MKV compressor - Wondershare UniConverter (originally Wondershare Video Converter Ultimate). It helps to shrink MKV files greatly and quickly by adjusting the encoder, bit rate, resolution, frame rate, and getting rid of the unwanted part. Wondershare MKV compressor is compatible with both Windows and Mac systems so that you can reduce MKV file size easily without any limitation. It supports 1000+ video and audio formats for you to compress and convert formats, you can edit videos with real-time preview and convert MKV videos with more features.

Wondershare UniConverter - Your Complete Video Toolbox for Windows/Mac

  • Compress MKV files by changing video resolution, bit rate, encoder, video quality, cropping and trimming, converting formats, etc.
  • Shrink MKV videos with super fast speed and no quality loss on Windows/Mac.
  • Support 1000+ video/audio formats including MKV/MP4/MOV/AVI/WMV/MPEG for compression and conversion.
  • Edit MKV videos with features of cropping, trimming, rotating, adding watermarks, and others.
  • Transfer converted videos from PC/Mac to iPhone/Android devices easily via a USB cable.
  • Download videos to MKV from YouTube and other 10,000+ video sharing sites by pasting URL.
  • Supports batch processing to compress and convert multiple videos at a time.
  • Toolbox with additional functions like Screen Recorder, DVD Burner, GIF Maker, Fix Media Metadata, Cast to TV, and more.
  • Supported OS: Windows 10/8/7/2003/Vista/XP, Mac OS 10.15 (Catalina), 10.14, 10.13, 10.12, 10.11, 10.10, 10.9, 10.8, 10.7, 10.6.
Security Verified. 5,481,347 people have downloaded it.

Steps to Compress MKV Files Using Wondershare UniConverter

Step 1 Launch Wondershare MKV Compressor

After you've downloaded and installed Wondershare UniConverter on your PC/Mac, launch it and choose the Video Compressor section first. You can click on the + icon on the window to add the MKV video you want to compress. You can also drag and drop the MKV video to the interface directly.

launch Wondershare MKV compressor

Step 2 Customize Settings to Compress MKV Files

You can see the added MKV video information on the Video Compressor window. Change the parameters like video resolution, bit rate, file size, format, and others directly or by moving the progress bar.

  • File Size: Click the arrow to add or reduce the file size, or input the number directly to change the MKV file size.
  • Format: You're allowed to convert MKV to other formats like MP4/AVI/MPEG/WMV, for the more supported format, move to the How to Convert and Compress Videos to learn more.
  • Resolution: Change MKV video resolution to 480*320, 640*480, 720*480, 240*160, and more.

customize MKV compression settings

Step 4 Compress MKV File Size

You're allowed to check your compressed MKV video for 20 seconds by clicking on the Preview button. Finally, tap on the Compress button to compress MKV video size.

Part 2. Simple Steps to Compress MKV File Size Online

Online MKV Compressors is an online platform designed by Wondershare so that the users can learn how to compress MKV files without losing quality online. With the help of this online tool, the users can resize the video for free. It doesn't even leave a watermark on the compressed files. The platform has a wide array of file format support for uploaded and target videos, you can reduce the size of the video as much as you want to. The simple steps on how to compress MKV files online are list below:

Step 1: Visit the official website and you will see a small space where you can add files for compression. You can also use the drag-and-drop method to directly load the file. Or hit the + icon and locate your MKV file and then upload it to the website interface.

add MKV video to compress online

Step 2: Once the file is added, you will get options to change the video resolution and size. You can also change the format of the media file.

set compression parameters

Step 3: Finally, hit the COMPRESS button and the MKV video will be compressed quickly. After the compression process, click on the Download button and the file will be saved on your computer.

Part 3. Other 3 Ways to Compress MKV Files Free

There are other free tools that would allow you to compress MKV files for free. Some open-source video tools with compress functions are reliable and completely free. As the MKV files are big and heavy, after compression you will have the same file in a smaller size. Here are the 3 best methods to compress the MKV files for free.

1. Wondershare Free Video Converter

Wondershare Free Video Converter is the free version of Wondershare UniConverter, both of them have similar functions and interface, you can even follow the same steps in Part 1 to compress MKV video for free with Wondershare Free Video Converter. It can be used on both Windows and Mac systems, and it also has many additional functions such as Video Download, Video Transfer, DVD Burn, and some small tools. MKV and other 1000+ video formats are supported by this free MKV compressor, you're allowed to compress MKV to MP4 easily with this free MKV compressor.

compress MKV files free


  • Compress MKV videos free with fast speed and high-quality output.
  • Trim and crop MKV files before compressing.
  • Change video resolution, bit rate, quality, format to reduce MKV file size for free.


  • It has a watermark on the video like most free tools.

2. HandBrake

HandBrake is another tool that is open-source and hence can be used on any OS. The software even has custom presets that would allow you to change the size of the media files quickly. The main function of the software is transcoding. HandBrake can easily process the common and popular media file format including MKV. It is one of the best and most useful cross-platform media converter and compressor to compress MKV on Mac. You can choose among a variety of options and can significantly reduce the video size.

compress MKV files with HandBrake


  • The software also supports batch scan and queuing.
  • It can change the bit rate of the video without affecting the quality.


  • The interface of the software is quite complicated.

3. VLC

As the MKV files occupy a lot of space in the storage, it is better that you compress them with VLC. Many users will be amazed to learn that they can reduce the file size with the help of this software. VLC has many hidden functionalities and video compression is one of them. Once you've learned how to compress MKV files to a smaller size with VLC, it will be easy for you to compress the files without installing or downloading any additional software. VLC is not only the best media player worldwide; it also has some additional functions which are quite helpful. The software has a wide array of format support so that you can play, convert, and compress files of any format.

compress MKV files free with VLC


  • It also allows the users to perform editing on the video files.
  • You can change the frame rate and bit rate of the video.


  • The software lacks advanced compressing options.

Conclusion: Now you have known multiple methods to compress MKV video size online and free. But if you want to own a compressor which can compress MKV without losing video quality and get more related features, then Wondershare UniConverter (originally Wondershare Video Converter Ultimate) is the best choice as the online and free tools have many limits on file size, compressing quality, and compressing speed.

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Christine Smith

Christine Smith

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