to 4AB — one identity across every product
No passkey on this device? Create one — it never leaves the device.
Whichever you pick, the browser is handed a short token that says nothing about you, and this server exchanges it for the identity. A page script can see that someone signed in; only the server learns who.
Some providers cannot prove an email address. Those sign-ins let you look around; email and WhatsApp still have to be confirmed before anything is bought, changed or sent.