Which one is worth more?
Tap the book that resells for more. Prices are revealed after you pick.
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How the BiblioScan Duel works
Each round puts two real books side by side, and one of them resells for more. Tap the one you think is worth more: both prices are revealed right after your pick.
The prices come from BiblioScan’s data. Each one is the median of the book’s last sales, the same figure the app shows for every book it recognizes on a shelf photo. Here, they’re US market prices, in dollars.
Spotting value at a glance is exactly the instinct resellers sharpen at every book sale. To check a book you own, run its ISBN through the free ISBN lookup, or photograph a whole shelf with BiblioScan: the AI identifies every book and shows its resale price.
Duel FAQ
Where do the duel prices come from?
From BiblioScan’s data: each price is the median of the book’s last sales, the same figure the app shows when it recognizes a book. These are US market prices, in dollars.
Is the BiblioScan Duel free?
Yes. The duel is free and needs no account, with 15 new duels every day.
Why is one book worth so much more than the other?
Resale price depends on demand and on how many copies of that exact edition are for sale. An out-of-print book with few copies left can sell for far more than a recent bestseller printed in huge numbers.
How do I find out what my own books are worth?
Photograph a shelf with BiblioScan: the AI recognizes each book from its spine and shows its resale price. For a single book, the free ISBN lookup tells you in seconds whether it’s worth reselling.