Thumbnail Tester

See what works. Know what to improve.

Public videos only. Shorts and private videos are not supported.

Your thumbnail will appear here

Paste a video link above to get started.

Your scorecard will appear here

Add a thumbnail to see what works and what to improve.

  • Mobile readability
  • Subject clarity
  • Text readability
  • Contrast & color
  • Composition
  • Technical quality

One clear score. Prioritized improvements backed by visible evidence.

3 free checks daily, then 1 Credit each. Resets at 00:00 UTC.

We analyze the image only. No YouTube Studio access.

HOW SCORING WORKS

A repeatable rubric, not a magic CTR number

01

Read

Upload an image or paste a public YouTube link. Only the thumbnail image is scored; video titles are shown as source information.

02

Evaluate

The image is reviewed for mobile readability, subject clarity, text readability, contrast, and composition.

03

Calculate

Thumbrix checks image dimensions and aspect ratio, then combines all six dimensions into a weighted score.

IMPORTANT LIMIT

A design score is not your actual CTR

The result assesses how clearly a thumbnail communicates visually. Real CTR also depends on the audience, topic, traffic source, recommendation context, competition, and title. Use the score to choose what to test, then confirm the winner with YouTube Studio experiments.