This runs in your browser. Nothing is uploaded. Longer clips take longer here than they would on a fast server — that is the trade-off for not sending the file.
About Video contact sheet
Builds a grid of frames from a clip as one PNG, in the browser, with no upload.
A 3×3 tile at one frame per second is the default. Short clips may not fill the grid; FFmpeg will error or pad oddly. This is a glance sheet, not a filmstrip editor. Extract frames if you want the stills separately so you can pick later.
Video contact sheet runs FFmpeg compiled to WebAssembly in this tab. The first visit of a video or audio tool fetches about 30 MB from this origin; after that it can stay cached. Your file is not in that download and is not POSTed anywhere. GPL FFmpeg, single-thread, same origin, no COEP experiment. That is the same encoder as convert, trim, and compress — this page is just a different argument list, with the same honesty about what the core cannot mux.
You can open the network panel and watch. Encoding a long clip on a phone is slow because it is your CPU. That wait is the trade for not handing the file to a converter you found in a search ad. Reverse and boomerang cap duration so a two-hour file does not try to live backwards in RAM. If a codec inside a familiar extension is missing from this core, you get an error rather than a silent broken file. Subtitle generation and stem splitting are not here; I will not pretend they are. Missing is better than a watermarked demo.
How to use Video contact sheet
- 1Drop a clip.
- 2Click Make sheet, then download the PNG.
What it won't do
- Fixed 3×3 grid.
- Needs enough duration to fill tiles.
Common questions
Does a contact sheet upload the video?
No.
Can I pick the frame times?
Not on this pass. fps=1 and a 3×3 tile. Extract frames if you want to choose later.
Why PNG not JPEG?
A sheet of frames is graphics. PNG is the honest still. Compress it yourself if you must email it.
Related tools
Why this one doesn't upload your file
There is no server to upload to. This page is a static file, and the work happens in your browser using the same graphics and WebAssembly code that renders every other site you visit. Your file is read from disk into memory, processed, and handed back as a download. Once the page has loaded you can disconnect from the network entirely and it keeps working. The longer explanation