Play MKV
MKV files the browser can't open are remuxed to MP4 on your device and played right away. No upload.
Drop a folder or files here
JPG · PNG · WebP · GIF · BMP · AVIF · SVG · HEIC · PSD · AI · TIFF · camera RAW · PDF · HWP · Word · PPT · Excel · DWG/DXF · MP4/WebM/MOV/MKV/AVI/WMV · MP3/WAV/WMA/AIFF · TXT/MD/CSV/JSON/HTML — subfolders included
This browser doesn't support the folder-open dialog, so the standard folder picker is used. Files are read only on your device.
Viewer pages by format
Popular formats have their own page. Whichever page you are on, files of any other supported format open just the same.
- View HEIC photosHEIC·HEIF·HIF
- View PSD filesPSD·PSB
- View AI filesAI
- View TIFF filesTIF·TIFF
- View camera RAW photosCR2·CR3·CRW·NEF…
- Play MKVMKV
- Play AVI and DivXAVI·DIVX
- Play RMVB and RMRM·RMVB
- Play WMVWMV·ASF
- Play FLVFLV
- Play TS and M2TSTS·M2TS·MTS
- Play WMAWMA
- Play APE and lossless audioAPE·WV·TTA·MPC
- Open EML and MSG emailEML·MSG
- Read EPUB ebooksEPUB
- View Jupyter notebooks (ipynb)IPYNB
- Open legacy Word (.doc)DOC
- View DICOM medical imagesDCM·DICOM·DIC
- View STL and OBJ 3D modelsSTL·OBJ
- Open ZIP and TAR archivesZIP·TAR·TGZ·GZ…
- Read CBZ comicsCBZ
- View certificate files (PEM, CRT, CER, DER)PEM·CRT·CER·DER…
- View SRT and SMI subtitlesSRT·VTT·SMI·SAMI…
- Preview font files (TTF, OTF, WOFF)TTF·OTF·WOFF·WOFF2…
Word, PowerPoint, Excel, HWP, and CAD have their own document viewer pages. Full file viewer →
MKV (Matroska) is the most common container for downloaded video, yet the browser's <video> element can't open it. This page remuxes MKV to MP4 on your device and plays it right away. Since the video inside is usually H.264, it takes a few seconds and loses no quality.
How to use it
- 1Click 'Choose MKV files' or drop files onto the page. A whole folder works too.
- 2Click a file in the grid to start preparation — the container is first remuxed to MP4 (a few seconds), and if the browser can't decode that codec it is converted automatically with a progress indicator.
- 3Once ready it plays in place. ← → for the next file, F for full screen, Esc back to the grid.
How it works
The video and audio streams inside the MKV are moved as-is into an MP4 container (no re-encoding). With H.264 + AAC/MP3 that's the end of it and quality is untouched. If the video is HEVC (H.265), VP9, or AV1 it plays directly when the browser can decode it, and is converted to H.264 when it can't.
Preparation runs on ffmpeg.wasm inside the browser. The engine (about 30 MB) is downloaded once on first use and cached after that. Prepared results are held in memory briefly and vanish when the tab closes. Files over 900 MB don't fit in browser memory — convert them first with the Video Converter tool.
Limits
Subtitle tracks (SRT/ASS) inside the MKV and extra audio tracks are dropped in the remux — only the first audio track is kept. For subtitles, load a subtitle file alongside the video in the Media Player tool. Files that need conversion take time in proportion to their length (a few minutes for a 10-minute video).
Good for
Checking what a downloaded MKV contains, work PCs where installing a player is blocked, and watching MKV on a Mac or iPad.
Frequently asked questions
Is quality reduced?+
When only remuxed (most H.264 MKVs) the data is untouched, so no. Re-encoding happens only when the codec isn't supported and conversion is needed.
Subtitles don't show.+
Subtitle tracks embedded in the MKV aren't carried into the playback copy. If you have a matching .srt or .smi file, open both in the Media Player tool.
Does a 5 GB MKV work?+
Up to 900 MB. The prepared copy has to fit in browser memory, so shrink larger files first with the Video Converter or Video Compress tool.