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Play a MKV video online, free

Play and convert .MKV videos online. Watch Matroska video and convert MKV to MP4 or MP3, free with no VLC needed.

Drop your .MKV file here

Opens your .MKV file right here.

Choose file
Inspect up to 4 GB · convert up to ~500 MB
No file handy?
Instant. Opens in seconds
Real FFmpeg compiled to WebAssembly
100% free. No watermarks
Engines load only when needed: MediaInfo (2.4 MB) to inspect, FFmpeg (32 MB, cached after first use) to convert.

How to convert a .MKV file online

Three steps, all tab.

01

Open your file

Drop your .MKV file and every video, audio and subtitle track inside is listed with its codec, resolution, frame rate and language.

02

Preview

See frames from across your .MKV file before you convert, even when your browser can't play the codec inside.

03

Convert

Pick MP4, WEBM or MP3, or repack to MKV without re-encoding. Play the result right here, then download it.

What is a .MKV file?

Everything worth knowing about Matroska Video.

An MKV file is a Matroska multimedia container that holds video, multiple audio tracks, subtitles and chapters in one file. Open it for free with VLC media player, or on Windows 11 with the built-in Media Player. If a TV or phone refuses the file, you can usually repackage (remux) it to MP4 with no quality loss.

Programs that open .MKV files

Windows
VLC media player, MKVtoolnix, Media Player (Windows 11) / Movies & TV, MPC-HC (clsid2 fork), mpv, PotPlayer
macOS
VLC media player, Elmedia Player, IINA
Linux
VLC media player, GNOME Videos (Totem), mpv
Android
MX Player, VLC for Android
iOS
OPlayer, VLC for iOS
.MKV format details
Full nameMatroska Video
DeveloperMatroska.org (open-source project, started by Steve Lhomme)
First released2002 (fork of the MCF project); EBML standardized as IETF RFC 8794 (2020)
CategoryAudio & Video
MIME typevideo/x-matroska
Signature1A 45 DF A3 (EBML header (non-printable))

Related viewers

Other free tools to open and preview your files.

Is my .MKV file uploaded to a server?

No. Your .MKV file is converted for you. The converted file is created in memory,.

Why is conversion slower than desktop software?

Browsers give web pages a single CPU core for this kind of work and no hardware video encoder. Short clips convert in seconds; for long 4K films a desktop app like HandBrake is faster. Use Start and Length to convert just the part you need.

Which output format should I pick?

MP4 plays on every phone, TV and browser. WEBM is an open format that's great for the web. MP3 keeps only the sound. MKV (no re-encode) is instant and lossless, but only changes the container.

Can I keep all audio tracks and subtitles?

The MKV (no re-encode) option copies every track as-is. MP4 and WEBM keep the first video and audio track, which is what most players use.

Why can't some files be converted?

Files protected with DRM (for example purchased iTunes .m4p songs or some .wmv rentals) are encrypted. We can show what's inside, but nobody can convert them without the key.

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