Proofhand

Proofhand · answers

Proofhand: every question answered plainly.

Proofhand is a CAPTCHA replacement: the visitor's browser solves a small proof-of-work challenge silently, the form carries a token, and the server verifies it once with a call shaped like reCAPTCHA's siteverify.

Questions

• What is Proofhand?
• Is Proofhand a CAPTCHA replacement?
• How much does Proofhand cost?
• Does it stop bots as well as a puzzle does?
• Will it work with my existing form?
• Can I charge AI crawlers instead of blocking them?
• Is Proofhand accessible?

Open Proofhand