YouTube Thumbnail CTR Score Calculator
Upload a thumbnail and get a click-through-rate score plus actionable fixes — analysis runs entirely in your browser, nothing is uploaded.
Drop a thumbnail (JPEG / PNG / WebP) here
Your image stays in your browser. Nothing is uploaded.
Frequently asked questions
- How does the CTR score work?
- We score four axes — resolution (vs 1280×720 at 16:9), contrast (luminance spread), saturation (HSL mean), and rule-of-thirds composition — and combine them into a weighted 0–100 overall score. No model training is involved; these are deterministic heuristics published in image-analysis literature.
- Is my thumbnail uploaded to your server?
- No. The image is analyzed entirely in your browser via the Canvas API. It never leaves your device. There is no server component, no logging, and no retention.
- How is this different from a Vision AI tool?
- Vision AI (GPT-4V, Gemini Vision) gives you natural-language critique but costs per request and requires uploading your image. CTR Predictor Lite is free, private, and instant, with a narrower but reproducible numeric score. We may add an optional Vision AI tier later.
- What image formats are supported?
- JPEG, PNG, and WebP. For best results, export your thumbnail at 1280×720 or larger with a strict 16:9 aspect ratio, which is what YouTube renders at the top quality tier.
- Can I use this on mobile?
- Yes. The tool runs in any modern browser including iOS Safari and Chrome on Android. Uploading from the device camera roll works.
- How many free uses do I get?
- Five uses per browser with no account required. After that, a single subscription unlocks unlimited use across every tool in the BonBonTools catalog.