Free YouTube Thumbnail Analyzer — Youtop.ai

Review a YouTube video thumbnail for brightness, contrast, faces, text density and image quality. Free, no signup.

Review a thumbnail's brightness, contrast, color balance, face and text density, and format-specific dimensions. Select video (16:9) or Shorts (9:16). These are technical image checks, not a measurement or prediction of CTR.

Use the results to inspect a cover before publishing and decide what, if anything, to revise.

How to use

  1. Select video or Shorts, then upload your thumbnail.
  2. Review the brightness, contrast, and color scores.
  3. Check the face and text density results.
  4. Check the dimensions against the selected format: 3840×2160 for videos or 2160×3840 for Shorts.
  5. Review the technical checks, make any changes you think are useful, and check the image again.

How to use the result

Measures the supplied image and reports technical and visual signals. It does not measure viewer preference.

  1. Read the cover at a small display size.
  2. Confirm the selected video format matches your upload.
  3. Compare the image with a second cover.

Frequently Asked Questions

What is the best YouTube thumbnail size?

YouTube recommends 3840×2160 for videos and 2160×3840 for Shorts. Check its current upload guidance for format and device limits. Choose video or Shorts in this tool so its size and ratio checks use the right format. Its upload limit is 8 MB per image.

How does the YouTube thumbnail analyzer score CTR?

The analyzer scores 7 technical signals: brightness (100-180 luma), contrast (55-90 standard deviation), saturation (90-170), face count (1 as a reference, 3+ flagged as crowded), text density (8-18% edge ratio as a reference), resolution (3840×2160 for videos, 2160×3840 for Shorts), and aspect ratio (16:9 or 9:16). The weighted average is a 0-100 image score, not a CTR measurement or prediction.

What colors boost YouTube thumbnail CTR?

High contrast can help separate a thumbnail's subject, but no color palette guarantees higher CTR; results depend on the image and audience. The analyzer extracts your thumbnail's top 5 dominant colors for review.

Should YouTube thumbnails have faces?

A clear face can be one way to focus a thumbnail when it fits the content. The analyzer detects faces and flags 3+ as crowded. This is a technical check; review the actual audience response after publishing.