YouTube Thumbnail CTR Predictor
Upload any thumbnail. Gemini Vision scores it 0–100, predicts a CTR tier, and tells you specifically what to change. No watermark, no signup, no email gate.
What the model scores
Six dimensions tuned for dark-niche YouTube (true crime, mystery, conspiracy, paranormal, dark history). Other niches still benefit — the underlying mechanics of attention are the same.
- Faces — presence, scale, emotional intensity (shock / dread / mystery beats neutral).
- Text overlay — legibility on mobile, hierarchy, dark-channel keyword density.
- Contrast — subject readability against background; a thumbnail invisible at small sizes loses the recommendation surface.
- Composition — focal point, rule of thirds, breathing room.
- Mood — dark / mysterious / dramatic / cinematic feel matching the niche.
- Color — dominant palette + accent colors that pop in the YouTube grid.
Frequently asked questions
How is the CTR prediction generated?
Gemini 2.0 Flash (Vision) scores the thumbnail across six dimensions tuned for dark-niche YouTube: face presence + emotional intensity, text-overlay legibility on mobile, contrast, composition, mood, and color palette. The output is a composite 0-100 score plus a qualitative tier (low / mid / high) with a one-sentence rationale.
Is the predicted CTR an actual percentage?
No — and any tool that claims to give you a specific percentage from a single image is lying. Real CTR depends on the title, the audience, the recommendation surface, the hour of day, your channel's past performance, and a dozen other factors. We give a tier (low/mid/high) which is honest about uncertainty, plus a 0-100 score for relative comparison between your own thumbnail variants.
What file formats are supported?
JPEG, PNG, and WEBP. Max 6 MB. YouTube's native thumbnail size is 1280×720 — uploading at that resolution gives the most representative score.
Why does the title help?
A thumbnail and a title work together: a thumbnail that looks "neutral" might be perfectly tuned for an evocative title. The model uses the title as context for whether the visual is doing its half of the job.
Are my uploaded images stored?
No — we forward the image to Gemini for analysis and return the result. Nothing is saved server-side. Each call is independent.
How is this different from connecting my channel to YouDark?
This is a one-shot analyzer. The full Thumbnail Lab inside YouDark scores against your channel's historical CTR baseline (so a 65-scored thumbnail might be great for one channel and weak for another), and lets you schedule A/B tests inside YouTube itself.
Other free tools
One-shot vs scored against your channel
The full Thumbnail Lab in YouDark compares against your channel's historical CTR baseline and lets you schedule A/B tests inside YouTube. Connect to unlock.
Open the channel scan