The definition
A video contact sheet (also called a thumbnail sheet, filmstrip or storyboard grid) is a single image containing N frames sampled at regular intervals from a video, typically labeled with each frame's source timestamp. The uniform spacing is what makes it honest: every cell is the same distance apart in time, so the sheet reads as a clock as much as a picture.
Who uses contact sheets today
Video editors use them to log dailies and plan cuts. Investigators and lawyers use them to index surveillance footage in a filing-friendly format. Wildlife researchers use them to summarize camera-trap cards. Teachers hand them out as lecture overviews. Designers use them as storyboards. The common thread: someone needs to see a video's structure without watching the video.
What a good sheet includes
Timestamps on every cell (the whole point is locating the moment in the source), a grid size that keeps cells readable (16–24 cells is the sweet spot), and enough width per cell to recognize content — 400–500 px per cell survives zooming; 100 px does not. Denser is not better: a sheet you cannot read summarizes nothing.
Making one in a browser
The Video Contact Sheet tool samples your video, lays out the grid at your chosen size, stamps the timestamps, and renders a single JPG — locally, with no upload. Choose the frame count to match how often your video changes: slides want few cells, action wants many.
Contact sheet vs storyboard vs filmstrip
A storyboard is drawn before shooting; a contact sheet is sampled after. A filmstrip is usually a single horizontal row — good for a short clip, bad for an hour. The grid contact sheet scales: 48 cells in 6 columns still fits one screen.