Book Cover Thumbnail Tester
Free tool: upload your book cover and instantly see how it looks at Amazon actual thumbnail size (90x144px). Test readability, genre clarity, and visual impact before you publish. No signup, no uploads to any server - everything happens in your browser.
Test at Real Sizes
See your cover at exact Amazon pixel heights: search, category, also-bought, and ad.
Shelf Simulation
See your cover sitting among competitors on a virtual Amazon shelf.
Thumbnail Checklist
Score your cover on 6 critical thumbnail readability factors.
100% Private
No uploads, no signup. Your images never leave your browser.
Drop your book cover here
or click to browse — PNG, JPG, or WebP
Click or drop again to replace
Amazon Size Preview
Your cover at the exact pixel heights Amazon uses. If you can't read the title here, neither can your buyer.
Shelf Test
Your cover sitting on a virtual Amazon shelf. Does it pop or disappear?
Thumbnail Checklist
Tick off each item while looking at the smallest previews above. Be honest.
This is exactly what The Art Director Method using Nano Banana teaches you to do right.
Turn Nano Banana from a slot machine into your creative partner.
Get the Guide - $19.99
The Art Director Method
Using Nano Banana
The method that turns Google Gemini's Nano Banana from a slot machine into your creative partner. 88 pages. Works today.
- ✓ The Story Context Method
- ✓ Generation Prompt Template
- ✓ Art Director's Edit Process
- ✓ Full Wrap Tutorial
- ✓ 6 Real-World Swipe Files
- ✓ Genre Vibe Cheat Sheet
Instant PDF download
Digital file - all sales final
"I spent $400 on a cover designer and wasn't happy. Made a better one myself with this guide in two hours."
- Verified buyer