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YouTube Thumbnail Rater
A free YouTube thumbnail rater that scores your image out of 100 and gives actionable feedback. Upload any JPG, PNG, or WebP thumbnail — the tool checks aspect ratio, resolution, file size, contrast, and orientation, then returns a grade with specific improvement tips.
What score does your thumbnail get?
How is the thumbnail CTR score calculated?
The rater checks five key technical criteria that directly affect how well your thumbnail performs on YouTube.
| Check | What passes | Why it matters |
|---|---|---|
| Aspect ratio | Between 16:9 (1.78:1) | Non-16:9 images are letterboxed or cropped by YouTube, cutting off part of your design. |
| Resolution | ≥ 1280 × 720 px | Low resolution looks blurry on Retina screens and large monitors. |
| File size | Under 2 MB | YouTube rejects thumbnails over 2 MB at upload. |
| Contrast range | Luminance range ≥ 80 | Low contrast text is invisible at 168px (YouTube Search size). |
| Orientation | Landscape (width > height) | Square or portrait images look wrong in the 16:9 video player. |
Thumbnail rating — questions answered
What does a good thumbnail score look like?+
A score of 80–100 (Grade A) means all five technical checks pass. A score of 60–79 (Grade B) means one or two minor issues exist. Below 60 means there are significant technical problems affecting CTR potential.
Does a high score guarantee a good CTR?+
The rater checks technical quality factors. It cannot evaluate design quality, hook strength, niche relevance, or emotional appeal — which often have more impact on CTR than technical specs. Use this alongside visual testing in the Thumbnail Tester.
Is the rater free to use?+
Yes, completely free. No account, no credit card, no watermarks.
More ways to improve your thumbnail
Low score? Let AI generate a better thumbnail.
CTRpilot generates high-CTR variants in seconds — right size, contrast, and resolution. Get 1 free thumbnail, no card required.
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