Thumbnail Tester
AI that analyzes high-performing thumbnails in your niche and generates layouts that outperform generic templates.
How it works
How to use the thumbnail tester
AI that analyzes high-performing thumbnails in your niche and generates layouts that outperform generic templates.
Upload one or more thumbnails
Start with your main thumbnail and add alternatives to compare quickly.
Set title and keyword context
Add your video title, then optionally load search competitors or a specific channel.
Analyze and review score
Use the right analysis sidebar to identify what is already strong and what should be fixed first.
Generate better variants
Create a stronger thumbnail prompt and optimized title options directly from your analysis.
FEATURES
Thumbnail Tester Features
AI that analyzes high-performing thumbnails in your niche and generates layouts that outperform generic templates.
Analyze thumbnail
Get an overall score plus metric breakdown for contrast, faces, color pop, and text readability.
Load competitors
Pull keyword-based YouTube competitors so you can preview your thumbnail against real context.
Load channel videos
Compare your thumbnail against a specific channel's recent uploads using handle, URL, or channel ID.
3 YouTube preview views
Preview in Search Results, Homepage Feed, and Suggested Sidebar contexts.
Desktop + mobile preview
Toggle desktop/mobile to validate readability and composition before publishing.
Multi-Thumbnail upload
Upload multiple variants, switch instantly, and remove options as you iterate.
Generate optimized titles
Generate multiple title options from your topic and keyword directly in the analysis panel.
Generate better thumbnails
Create a thumbnail improvement prompt from your score and suggestions with one click.
Why creators use this thumbnail tester
Built for anyone who wants faster production and higher CTR.
Real YouTube context
Preview how your thumbnail appears in the three places that drive discovery: search results, homepage feed, and sidebar suggestions
Clear analysis panel
Get an overall score, metric-by-metric breakdown, and prioritized fixes for contrast, faces, color pop, and text readability.
Fast iteration workflow
Upload multiple variants, switch instantly, and generate new thumbnail and title ideas from the same analysis result.
Frequently asked questions
What is a good YouTube thumbnail size?
Use 1280x720 pixels in a 16:9 ratio. Keep the file under YouTube's upload limits and verify readability at small sizes.
How can I test if my thumbnail stands out?
Load competitors with a keyword or channel, switch to the same context your audience sees, and use Stand Out mode to run a quick visual isolation test.
Can I compare multiple thumbnail options?
Yes. Upload multiple variants in Setup and click each one to instantly update preview, score, and suggestions.
Does this work for mobile YouTube viewers?
Yes. Toggle to mobile preview and review how thumbnails and text hold up at smaller feed sizes.
What should I improve first for higher CTR?
Start with the weakest metric in the analysis panel. Most creators see the fastest gains by fixing text readability and contrast first.
What's the best font size for thumbnails?
Large enough to read at mobile size. Test by viewing your thumbnail at small scale before downloading.
Stop losing views to mediocre thumbnails
Generate studio-quality thumbnails that stop scrolling and drive clicks in seconds. No design skills needed.
+50% average CTR increase
2× faster production speed
90% reduction in design cost
