YouThumb - YouTube Thumbnail Tester & Preview

Test your YouTube thumbnails before publishing. Preview in the real YouTube feed and get AI feedback to maximize clicks.

Stop guessing if your thumbnail will get clicks. YouThumb lets you preview your thumbnail inside the real YouTube feed — surrounded by actual competitor videos — before you publish. Upload your design, type your title, and instantly see exactly what viewers see. PREVIEW IN THE REAL FEED • Home Feed, Search Results & Watch Sidebar • Place your thumbnail at any position in the feed • Switch between Dark & Light YouTube themes • Preview on Mobile & Desktop layouts STRESS-TEST FILTERS • Blur Test — Can viewers recognize it at a glance? • Grayscale Test — Does it stand out without color? • Mobile View — How does it look on phone screens? AI-POWERED FEED SCAN • AI ranks your thumbnail against 5 real competitors • Get a clear Feed Rank and actionable improvement tips • Know exactly what to fix before you publish HOW IT WORKS 1. Open YouTube and click the YouThumb extension 2. Upload your thumbnail and enter your video title 3. Preview it in the real YouTube feed 4. Run an AI Scan to see how you rank against competitors 5. Fix what needs fixing. Publish with confidence. FREE TO USE • Preview and stress-test — free, no sign-up needed • AI scans use tokens — 100 free tokens on sign-up • Works directly inside YouTube • No YouTube account connection required Perfect for YouTube creators, video editors, and thumbnail designers who want more clicks and better CTR. Test your thumbnail before publishing. Get the clicks you deserve.