Slabscout is a free Chrome extension for Whatnot card streams. Press one key while the seller holds a card up — get its identity, market value, live asks, and what it actually sold for. In seconds. No tabs, no typing, no guessing.
Whatnot card auctions run ~10 seconds. By the time you've opened eBay, typed the card, and filtered the junk, it's gone — or you overpaid. Slabscout does the whole workup in one keypress.
AI reads the stream frame — player, set, year, card number — and then verifies the number against real checklists before showing you anything. Wrong-card comps are the enemy; we built three independent checks against them.
The big number is a sold-derived market value per grade — raw, PSA 9, PSA 10 — from millions of real transactions, plus how often the card actually sells per year (liquidity matters when you have to exit).
Sellers' asking prices vs. what buyers recently paid — side by side. Asks run high; Slabscout says so instead of pretending an ask is a value. Every number links back to eBay so you can verify in one click.
Add Slabscout to Chrome. No account, no signup, nothing to pay us — ever.
Grab a free Google AI key (about a minute, no credit card) and paste it once in Settings. It stays in your browser.
When the seller holds a card up, press S. Identity, value, spread, comps — before the bidding ends.
The Chrome Web Store listing is in review. Until it's live, the manual install takes about a minute: