Three cards. One secret.
Each card holds one share of five. No single card tells you anything. Any three of them, together, give the secret back.
This page reads the five demo cards and nothing else. A real card is read by an offline tool, never by a web page.
The demo cards
How this page works
The share on a card travels in the part of its web address after the #. Browsers never send that part to a server, so the share reaches this page without passing through one. The reassembly runs here, in your browser.
If you use the scanner, the camera frames are read in your browser too: the code is decoded on your device and never leaves it.
This page is not allowed to make a network request in the background — no upload, no analytics, no error reporting. The browser enforces that, not us, and the share is taken out of the address bar the moment it is read.
A real set works the same way, with one difference that matters: a real card is read by an offline tool you download and keep, not by a web page. Nothing published on the internet, including this page, should ever be given a real share.