What the thumbnail rater scores
You get one overall rating from 0 to 100, and underneath it three separate scores. Each one answers a different question a scrolling viewer asks in about a second.
- Visual hierarchy: is there one clear focal point, or are the face, the text, and the background all fighting for attention?
- Readability: would the words and the main subject still read at the small size a thumbnail has in a phone feed?
- Clickability: does the image make someone curious, or does it look like the ones they have learned to scroll past?
You also get a short written roast and three or four specific fixes, so the rating tells you what to do next instead of just handing you a number.
How to read your rating
There's no official scale for thumbnail ratings, so treat these bands as a rough guide to how urgent the work is, not as a promise about clicks.
- Below 40: something basic is wrong, usually unreadable text, no clear focal point, or a muddy image. Fix the biggest issue and rate it again.
- 40 to 59: the idea is there but the execution is weak. Look for the lowest of the three sub-scores and start there.
- 60 to 79: a solid thumbnail with one or two clear improvements available.
- 80 and above: strong on the basics. Further gains usually come from testing ideas on real viewers.
The three sub-scores matter more than the total. A thumbnail that scores well on clickability but poorly on readability has a specific, fixable problem. The total alone hides that.
How to raise a low score
Work on the weakest sub-score first. Here's what usually moves each one.
- Low visual hierarchy: remove elements until one thing is clearly the subject. Make it larger and give it an outline or brighter tone so it separates from the background. See six thumbnail layouts that work.
- Low readability: cut the text to three or four words, use a heavy font, and add a thick outline. Our guide to thumbnail text explains the common mistakes.
- Low clickability: add an honest hook such as a number, a contrast, or an unfinished situation, and check that it doesn't repeat your title. See how to write hooks without clickbait.
A quick example of how the sub-scores differ
Imagine a thumbnail with a strong, well-lit face, but three lines of thin text placed over a busy background. It would likely rate well on clickability, because the expression creates curiosity, and poorly on readability, because the text disappears at feed size. Fixing that one problem, by cutting the text to three bold words, is a much smaller job than redesigning everything. That's what separate scores are for.
Rate several versions, not just one
The most useful way to use a thumbnail rater is to compare. Make two or three genuinely different versions, rate each one, and look at where they differ. If one wins on readability and another wins on clickability, you know what to combine. Change one thing at a time so you can see what caused the difference.
You can use a free rating five times a day, which is enough to compare a few versions of the same thumbnail. Once you have a favorite, preview it in a real-size feed with the thumbnail preview tool.
Rater, checker, or A/B test?
These three names get mixed up, but they do different jobs.
- The rater (this page) scores the design and explains each part.
- The thumbnail checker runs the whole pre-upload routine: design, file size and format, and feed preview.
- An A/B test compares versions with real viewers after you publish. Here's how to A/B test YouTube thumbnails.
Prefer to score by hand? The 7-point checklist to rate a YouTube thumbnail takes about two minutes and needs no tool.
Frequently asked questions
Is the thumbnail rater really free?
Yes. You get five free ratings a day with no account and no credit card. If you need more, see the pricing page.
What file types can I rate?
JPG, PNG, and WEBP images up to 5 MB. Exporting a thumbnail at 1280 by 720 pixels as a JPG or PNG is more than enough.
Do I need to add my video title?
No, but it helps. With a title, the rater can also comment on whether the words on the thumbnail add something the title doesn't already say.
Does a high rating mean my thumbnail will get more clicks?
Not with certainty. The rating is an AI opinion of the image based on design principles. Real click-through rate also depends on your title, your audience, and what appears next to your video. Use the rating to catch fixable problems, then confirm with real data.
Is my thumbnail saved?
No. The image is sent to the AI provider to generate the rating and returned to your browser. It isn't stored in a database or shared.
How is rating different from an A/B test?
A rating judges the design itself before you publish and takes seconds. An A/B test compares real viewer behavior after publishing and takes days. Rate first, then test the versions that survive.