Video Contact Sheet

Turn a video into one image with a grid of evenly spaced, timestamped thumbnails, without uploading the video.

Choose a video

or drop it here

The video is processed on this device and never uploaded.

MP4, MOV, WebM, MKV, AVI, WMV, FLV, 3GP, TS / MTS / M2TS or VOB / MPG

Files over 1 GB can be slow. Very large outputs need a browser that can save straight to a file.

How it works

Choose a video and set the number of columns and rows and the thumbnail width. The tool splits the video into equal parts and takes the frame in the middle of each part, so the sheet covers the whole video without starting on a black first frame.

Your browser decodes only those frames, draws each one into its cell with the time in the corner, and saves the grid as a single image of up to 100 thumbnails and 4096 pixels on the longest side. The video is not uploaded, and each frame is released from memory as soon as it has been drawn.

Supported files

Inputs: MP4, MOV, M4V, WebM and MKV in most browsers. AVI and FLV files with H.264 video are repacked with FFmpeg first (copied, not re-encoded) and then read with WebCodecs, timestamps included. Video the browser cannot decode (WMV, VOB / MPEG-2, MPEG-4 Part 2) is first decoded by FFmpeg into a full-quality intermediate copy, which takes longer; the sheet is then drawn with WebCodecs, timestamps included. Files FFmpeg cannot prepare use the slower FFmpeg.wasm engine.
Outputs: One JPEG, PNG or WebP image, up to 100 thumbnails and 4096 pixels on the longest side.

Limitations

At most 100 thumbnails (10 x 10). Larger grids shrink the thumbnails so the image stays within 4096 pixels.
Videos your browser cannot decode are processed with FFmpeg.wasm, which is slower, reads the whole file and cannot add timestamps.
Safari cannot write WebP images, so the sheet is saved as PNG and the page says so.
HDR videos give ordinary (SDR) thumbnails, so bright highlights can look flat.

Questions

Is my video uploaded?

No. The video is read by your browser on your device and never leaves it.

How are the thumbnails chosen?

The video is divided into as many equal parts as there are thumbnails, and the frame in the middle of each part is used. The time shown is the time of that frame.

Why are my thumbnails smaller than I set?

The whole sheet is limited to 4096 pixels on its longest side, so a big grid of wide thumbnails is scaled down to fit. The page shows the final size before you start.

Which format should I choose?

JPEG gives a small file that opens everywhere. PNG is lossless but much larger. WebP is the smallest.

Example

A 10-minute video with 4 columns, 4 rows and 320-pixel thumbnails gives a 1300 x 740 px sheet of 16 thumbnails, one from the middle of every 37.5 seconds (0:18, 0:56, 1:33 and so on), each labelled with its time.