Three Simple Steps
How Authentication Works
Upload
Take a photo or upload an image of the signature you want to verify.
AI Analysis
Our system compares against verified exemplars, applies expert-derived rules, and checks for known forgery patterns.
Get Your Verdict
Receive a confidence score, category breakdown, era assessment, and forgery risk analysis. All in seconds.
Real-World Scenario
Authentication at the Speed of eBay
A signed Harrison Ford photo hits eBay at 2 a.m. Buy It Now, $400. You know it’ll be gone by morning. Traditional quick opinion services take 24 to 48 hours. By then someone else owns it.
Grail Den gives you a confidence score in seconds, day or night, so you can make an informed decision before the listing disappears.
Expert Intelligence
Trained by Real Authenticators
Our authentication engine isn't generic image recognition. Each signer is individually profiled by expert authenticators who have studied their signing patterns across decades. Training is built exclusively on curated reference exemplars — items with verified provenance from leading authentication houses. Your submissions are analyzed for authentication only and handled according to our Privacy Policy.
FREE AUTOGRAPHS — THROUGH THE MAIL
Why pay $200 for a signed photo when you can get one for the cost of a stamp? Look up mailing addresses for over 200,000 celebrities, athletes, and public figures in our Through The Mail database. Plan your TTM campaigns, send your items out, and authenticate what comes back.
Quick Opinion Comparison
Autograph Authentication — Quick Opinion Comparison
How Grail Den compares to quick opinion services offered by traditional authenticators.
How do quick opinion services compare? The table below shows photo-based authentication services — not full mail-in certification.
| Service | Type | Cost | Turnaround | Notes |
|---|---|---|---|---|
| SWAU | Photo review | $10 | ~24 hours | Entertainment autographs only. Pass/fail opinion. Lifetime guarantee on witnessed items only. |
| Beckett (BAS) | Photo review | $10 | 24–48 hours | All categories. Pass/fail opinion. $10 credit toward full auth if submitted within 90 days. |
| PSA/DNA | — | — | — | QuickOpinion service discontinued April 2025. Full authentication starts at $20+ and takes 30+ business days. |
| JSA | — | — | — | No quick opinion service. Full authentication requires mail-in submission. |
| Grail Den | AI + Expert | From $0.80 | Seconds | Detailed confidence score, category breakdown, era assessment, forgery risk. 40+ entertainment signers. |
Credit Bundles
Deep Verify Credits
Purchase credits to run authentication assessments. The more you buy, the more you save.
Credits never expire. Use them whenever you need a verification.
Growing Database
40+ Signers and Growing
Expert-verified authentication profiles across film, television, and entertainment.
New signers are added as our expert authenticators onboard them.
Through The Mail
Plan Your Next TTM Campaign
200,000+ Celebrity Mailing Addresses
Look up mailing addresses for actors, directors, athletes, musicians, and public figures. Our Through The Mail database — the largest available — helps you plan autograph campaigns with current addresses for agencies, production companies, and management. Available to all Hunter and Scholar subscribers.
Beyond Authentication
The Complete Collector’s Platform
Authentication is just the beginning.
Global Hunt
15 Marketplaces. 8 Languages. One Search.
Search eBay US, UK, Germany, France, Italy, Spain, Australia, and more — all at once. Queries auto-translate so you find items listed in any language. Prices convert to your currency instantly.
TTM Database
200,000+ Celebrity Addresses
Plan your Through The Mail autograph campaigns with the largest mailing address database available to collectors. Actors, directors, athletes, musicians — look up anyone.
Collection Tracking
Your Collection, Organized
Catalog every piece with photos, provenance chains, and condition grading. Track value over time. Generate insurance reports for your entire collection with one click.
Market Research
142,000+ Auction Lots Analyzed
Research sold comps from Propstore, Heritage, Julien’s, and dozens more auction houses. See what items actually sold for — including buyer’s premium — so you never overpay.
Get Started
Ready to Verify?
Your First Assessment Is on Us.
Upload a photo, get your verdict in seconds. No credit card required to start.
Start FreeAuthentication assessments are informational tools only and do not constitute professional authentication, appraisal, or guarantee of authenticity. Results should be used as one factor in your purchasing decisions alongside other due diligence.