The Collector's Intelligence Platform
The AI-powered intelligence platform for collectors who refuse to settle. Search 15 global marketplaces in 8 languages. Track your collection. Verify authenticity. From $7.99/month.
Free to start · No credit card · Mac & iPhone apps coming soon
Signature Intelligence
See authentication confidence on every signed listing as you browse. No uploads, no waiting, no separate service.
Our system is trained by professional authenticators on thousands of verified signatures. 40+ signers and growing monthly.
Traditional authentication costs $30–150 per item and takes weeks. Get the same insight instantly, starting at less than a dollar per item.
Currently covering: Harrison Ford, Mark Hamill, Carrie Fisher, George Lucas, William Shatner, Leonard Nimoy, Steven Spielberg, and 30+ more.
Traditional quick opinion services charge $10 and take 24–48 hours for a simple pass/fail. Grail Den starts at $0.80 with detailed analysis in seconds.
Three Steps
Search signed collectibles on eBay through Grail Den
See instant authentication confidence scores on every listing
Know what's real before you spend
Your Arsenal
Every module built for obsessive collectors who demand precision, speed, and an unfair advantage.
A signed movie poster listed on eBay Germany has a German title — you'll never find it searching eBay.com. Grail Den translates your search into 8 languages, searches 15 international marketplaces simultaneously, converts every price to your currency, and surfaces items most collectors never see.
15 Marketplaces · 8 Languages · Auto Currency ConversionCatalog every piece with photos, provenance chains, and condition grading. Track value over time. Generate insurance reports. Import items from eBay purchases or CSV in bulk. Know your collection's true worth, always.
Value Tracking · Insurance Reports · Smart ImportAnalyze sold comps from major auction houses, market trends, and price history across 142,000+ historical lots. AI-powered insights surface opportunities before the herd catches on.
142K+ Auction Lots · 200K+ TransactionsLook up mailing addresses for 201,000+ celebrities, athletes, and public figures. Plan your Through The Mail autograph campaigns with the largest address database available.
201K+ Addresses · Always Updated Search 201,000+ AddressesGlobal Advantage
Your search, translated instantly. “Star Wars signed photo” becomes “Star Wars signiertes Foto” on eBay Germany, “Star Wars photo signée” on eBay France, and “Star Wars foto autografada” on eBay Spain. Over 1,100 collecting terms are protected so franchise names and key terminology stay accurate across every translation.
Most collectors only search eBay.com. They’re missing 14 other eBay marketplaces full of items listed in local languages at local prices. A prop that sells for $800 in the US might be listed for €400 on eBay Italy — if you can find it. Grail Den searches them all at once.
Every result shows the price in your currency automatically. No mental math, no googling exchange rates. See a lightsaber hilt on eBay UK for £350? You’ll see $440 right next to it. Compare across borders as easily as across the street.
The Scholar's Edge
AI features that give you an unfair advantage in the hunt.
Upload a photo of any autograph. AI compares it against verified exemplars, checks for known forgery patterns, and gives you a confidence score in seconds. Trained by professional authenticators on 40+ entertainment signers.
Not all sold comps are equal. AI separates outliers from true market signals, giving you the real price -- not the noise.
Bulk import your collection from eBay purchase history or CSV files. AI cross-references databases, fills in details, and builds your catalog automatically. Hours become minutes.
What Hunters Seek
Whatever you collect, Grail Den speaks your language.
Choose Your Path
Start free. Upgrade when the hunt demands it.
Free
Browse and discover. See what's possible.
Collector
$59.99/year — save 37%
For the serious collector. Authenticate everything.
Pro
$119.99/year — save 33%
Every advantage. Every insight. Every edge.
Deep Verify — upload your photo, get an instant PDF authentication report. No subscription required.
Credits never expire. Scholar members get 5 free credits every month.
The Den Awaits
Hunt smarter. Collect with confidence. Never overpay.
Enter the DenFrom the Vault
The truth about fake COAs and "premiere signed" memorabilia. Those hologram stickers are worth less than the paper they're stuck on.
ReadAuto-pen machines produce convincing signatures that fool most collectors. Learn the telltale signs.
ReadThat "signed" movie poster might just be a print. How to identify press-signed autographs vs the real thing.
ReadGrail Den Authentication is a research tool, not a certificate of authenticity. Our confidence scores are based on expert visual assessments across multiple authentication categories. For high-value items ($500+), we recommend supplementing with professional authentication from PSA, JSA, or a qualified expert.