Video Thumbnail Maker
Capture still frames from a video at even intervals, and optionally build a single contact sheet of the whole timeline.
Convert with this tool
or choose a file from your device — it is processed in this tab and never uploaded
Accepted: MP4, WebM, MOV and other browser-decodable containers
Files stay on your device. There is no upload, no queue and no watermark, so a conversion works even with the network switched off after the page has loaded.
Supported formats & processing
| Accepted input | MP4, WebM, MOV and other browser-decodable containers |
|---|---|
| Produced output | JPEG or PNG frames, plus an optional contact-sheet image |
| Processing | Web Audio API + canvas + native JavaScript encoders |
| Upload required | No — the file is read locally and never transmitted |
How to use this tool
- Add the videoIts duration and resolution are read from the container.
- Choose how many thumbnailsFour for a quick overview, nine for a contact sheet.
- Set the output width640 px is good for previews, 1280 px for a poster frame.
- Enable the contact sheet if you want oneEvery capture is tiled with its timestamp.
- Convert and download individuallyEach frame has its own download button in the result card.
About this tool
Thumbnails are needed constantly: a poster frame for a player, a preview image for a video platform, a set of stills for a documentation page, or a contact sheet to show a client the shape of an edit at a glance.
This tool seeks the video to evenly spaced positions, captures each frame to a canvas and encodes it as an image. The contact-sheet option tiles every capture into one image with the timestamp burned into each cell, which is the fastest way to review what is in a long recording.
Features
- Evenly spaced capture positions across the whole timeline
- Up to nine thumbnails in one job
- Optional single contact sheet with timestamps burned in
- Output width presets from 320 to 1280 px
- Individual download buttons for every frame
- Honest note on browser seek accuracy
Frequently asked questions
Can I choose the exact frames?
The captures are evenly spaced automatically. To grab a specific moment, cut that section with the video cutter first, then run the thumbnail maker on the clip.
How accurate are the capture positions?
The browser seeks to the nearest decodable frame, so the captured image can be a fraction of a second from the requested timestamp. The exact positions used are reported in the result card.
What is a contact sheet for?
It is a single image showing the whole timeline at a glance — useful for reviewing a long recording, documenting a shoot, or showing a client the pacing of an edit without sending them the video.
Why is my capture black?
If the seek landed before the first decodable frame, or the video uses a codec the browser cannot decode, the canvas stays empty. Try a different position, or convert the file to MP4 first.