Free tool · no sign-up
Free YouTube thumbnail check
Drop in a thumbnail and see how it holds up at the size people actually see it: on a phone, next to other videos. The check runs on your device, so the image is never uploaded.
How it works
- Size: 1280 × 720 stays sharp on TVs and desktops (10 points).
- Shape: 16:9, so YouTube adds no bars and crops nothing (10 points).
- Brightness: not so dark it vanishes in dark mode, not so pale it blends into a white page (15 points).
- Contrast: the subject has to stand out at phone size (25 points).
- Colour: one bold colour helps in a busy feed (15 points).
- Clutter: one subject and a few large words read better than lots of small detail (15 points).
- Corner: the bottom right sits under the video length badge, so keep it clear (10 points).
Questions
- Is my image uploaded?
- No. The image is read and scored in your browser. We only count that the tool was used.
- Does it judge faces or text?
- No. It measures things it can check reliably: size, shape, brightness, contrast, colour, detail and the corner. It does not read text or detect faces.
- Will the same image get the same score?
- Yes, every time. The checks are fixed rules, not an AI guess.
- Is it free?
- Yes, with no sign-up. There is a fair-use cap per network.
More free tools
- YouTube title score: Score a title out of 100 and see exactly what helped and what hurt. The same title always gets the same score.