reCAPTCHA

FREE anti-bot service that helps digitize books.
Easy to add, strong security, accessible to blind users.

What is reCAPTCHA?

reCAPTCHA is a free CAPTCHA service that protects your site against spam, malicious registrations and other forms of attacks where computers try to disguise themselves as a human; a CAPTCHA is a Completely Automated Public Turing test to tell Computers and Human Apart. reCAPTCHA comes in the form of a widget that you can easily add to your blog, forum, registration form, etc.

In addition to protecting your site, reCAPTCHA also helps us digitize old books and newspapers. Learn how reCAPTCHA works and join our forum.