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.MKV file extension

To open .MKV files on Windows, open with VLC or MPC-HC for full compatibility.

.mkv files are Matroska video containers. They can be opened with VLC, mpv, or other compatible media players.

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Last updated: March 19, 2026 · Reviewed by Julian Stricker

What “reviewed” means on this page
  • Format fit: whether the “what is this file?” description plausibly matches common real-world use of the extension, including category, typical MIME types, and aliases.
  • Opening paths: whether Windows / macOS / Linux steps read plausibly for current OS dialogs and default apps. Not every step was tested on every OS version.
  • Security framing: whether risk notes match the extension class (for example executables vs plain data) and whether affiliate wording does not contradict the security section.
  • Sources and further reading: external links should point to vendors, standards bodies, or other primary references where possible; not every detail is individually sourced.
  • Limits: this is clarity and safety-messaging QA, not a guarantee that every statement is exhaustive or that every binary you download is harmless. Pages without “Reviewed by” have not been through this editorial pass yet.

Full methodology in the Imprint — The Imprint also states where AI is used and what that does—and does not—replace.

Open on your device

Choose your operating system for a dedicated step-by-step opening guide.

Edit .MKV files

Need to change the content, not just open it? These editors work with .MKV files.

Movavi Video Editor

Cut, join and edit videos, add titles, music and effects.

Wondershare Filmora

Video editor with titles, transitions, effects and AI tools.

We may earn a commission when you use affiliate links. This supports our free file extension guides.

How to open .MKV files

Use these platform-specific instructions to open .MKV files safely.

Windows

  1. Open with VLC or MPC-HC for full compatibility.
  2. Consider installing K-Lite Codec Pack for broader support.

Recommended software: VLC media player (free) · mpv (free)

Full Windows guide

Mac

  1. Use VLC or IINA for playback.
  2. Convert to MP4 using HandBrake for better compatibility with other apps.

Recommended software: VLC media player (free) · IINA (free)

Full Mac guide

Linux

  1. Play using VLC or mpv.
  2. Use mkvtoolnix for editing and inspecting MKV files.

Recommended software: VLC media player · mpv

Full Linux guide

iOS

  1. Install VLC from the App Store.
  2. Consider transcoding to MP4 if playback issues occur.

Recommended software: VLC for Mobile (free)

Full iOS guide

Android

  1. Use VLC or MX Player for smooth playback.
  2. Switch to software decoding if hardware acceleration issues arise.

Recommended software: VLC for Android (free) · MX Player

Full Android guide

Security notes

  • Avoid downloading codec packs from untrusted sources.
  • Scan all downloaded media files with antivirus software.
  • Be cautious of files from unknown sources as they may contain malware.

Can't open this file?

These are the most common causes and fixes when .MKV files fail to open.

Common reasons

  • Subtitles are missing
  • Audio out of sync
  • Playback stutters or lags
  • The MKV video does not open or plays without sound in the built-in player

Fix steps

  1. Access the subtitle settings in your player.
  2. Manually select the desired subtitle track.
  3. Use MKVToolNix to set a default subtitle track.

Repair a damaged .MKV file

If the file opens with errors or not at all, a dedicated repair tool can often rebuild it. Work on a copy and keep the original file untouched.

Wondershare Repairit (Video)

Repairs corrupt or unplayable video files such as MP4, MOV and AVI.

We may earn a commission when you use affiliate links. This supports our free file extension guides.

Recover a deleted or lost .MKV file

If the file was deleted by mistake or the drive was formatted, data recovery software may be able to get it back. Stop writing to that drive right away, because new data can overwrite what you want to recover.

MiniTool Power Data Recovery

Windows software that recovers deleted or lost files from PCs and external drives such as HDDs, SSDs, USB drives and memory cards, after deletion, formatting or a crash.

Wondershare Recoverit

Windows and Mac software that recovers deleted or lost files from computers and external drives such as HDDs, SSDs, USB drives and SD cards.

We may earn a commission when you use affiliate links. This supports our free file extension guides.

OS-specific troubleshooting

Convert .MKV to other formats

Use conversion tools to change .MKV files into formats your software supports.

What is a .MKV file?

MKV is a container format that can hold an unlimited number of video, audio, picture, or subtitle tracks in one file. It is widely used for storing high-definition video and supports advanced features like chapters and metadata.

Background

The Matroska Video (MKV) format was developed as an open standard project to provide a flexible, extensible, and cross-platform multimedia container. It is particularly popular in the digital video community for its ability to store multiple audio tracks, subtitles, and chapters, making it ideal for movies and TV shows. Unlike other formats, MKV is not restricted by licensing fees, which has contributed to its widespread adoption. The format's flexibility allows for high-quality video and audio storage, often used in conjunction with codecs like H.264 and AAC. Despite its advantages, MKV files can sometimes be large and may not be supported by all devices or software without additional codecs or conversion.

Common MIME types: video/x-matroska

Further reading

Authoritative resources for more details on the .MKV format.

Common .MKV issues

Subtitles are missing

The player may not automatically select the correct subtitle track.

  1. Access the subtitle settings in your player.
  2. Manually select the desired subtitle track.
  3. Use MKVToolNix to set a default subtitle track.

Audio out of sync

Audio may not sync properly with video playback.

  1. Use VLC to adjust audio delay.
  2. Check for updated codecs or player versions.
  3. Remux the file with corrected audio sync using MKVToolNix.

Playback stutters or lags

High-resolution files may cause performance issues.

  1. Ensure your device meets the file's playback requirements.
  2. Try a different media player with better optimization.
  3. Reduce video quality or resolution if possible.

The MKV video does not open or plays without sound in the built-in player

MKV is a container that can hold many codecs. Built-in players, such as QuickTime on the Mac, do not support all of them.

  1. Open it in VLC, which plays MKV files with its own codecs.
  2. To convert it without quality loss, run ffmpeg -i input.mkv -c copy output.mp4 (works when the codecs fit into MP4).
  3. If that fails, re-encode it to H.264/AAC with HandBrake (free).

FAQ

Is MKV better than MP4?

MKV offers more flexibility with multiple tracks, while MP4 is more universally compatible.

Can I convert MKV to MP4 without re-encoding?

Yes, if the video and audio codecs are already compatible with MP4.

Why won't my TV play MKV files?

Not all TVs support MKV files natively; try using a media player or convert the file.

Similar file extensions

Compare related formats in the same category to find the right tool faster.

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