MKV (Matroska) is a flexible container used by OBS recordings, screen captures and many video tools. JPG is the universal image format: it opens everywhere and keeps files small. This tool takes the first frame of each MKV video and saves it as a JPG, without uploading anything.
How to extract a JPG thumbnail from MKV
- Drop your MKV videos in the box above, or click to pick them. You can add as many as you like.
- JPG is already selected as the output format. Switch on other formats if you want them too.
- Optional: open Advanced Settings to resize the thumbnail by percentage, width or height, and add more sizes.
- Click Extract Thumbnails, then download each image or all of them at once. Nothing is uploaded: everything runs in your browser.
Why save MKV thumbnails as JPG?
MKV files often do not open in photo apps or simple players. Extracting the first frame as an image is a fast way to preview or catalog them without installing anything. JPG is the safest choice for video thumbnails: video platforms, social networks, emails and content management systems all accept it, and the file stays light. Video frames have no transparency, so JPG loses nothing there.
Frequently asked questions
Which MKV files are supported?
MKV files whose video codec your browser can decode, typically H.264, VP8, VP9 or AV1. OBS recordings in H.264 work in every modern browser.
Is a JPG thumbnail good enough?
Yes. The frame is saved with a high quality setting, so it looks like the video, at a fraction of the size of a PNG.
Are my videos uploaded?
No. The first frame is decoded and saved as an image in your browser, on your device. Your videos are never sent to a server, so this works for private files too.