About 200 million CAPTCHAs are solved by humans around the world every day. In each case, roughly ten seconds of human time are being spent. Individually, that's not a lot of time, but in aggregate these little puzzles consume more than 150,000 hours of work each day. What if we could make positive use of this human effort? reCAPTCHA does exactly that by channeling the effort spent solving CAPTCHAs online into "reading" books.
To archive human knowledge and to make information more accessible to the world, multiple projects are currently digitizing physical books that were written before the computer age. The book pages are being photographically scanned, and then transformed into text using "Optical Character Recognition" (OCR). The transformation into text is useful because scanning a book produces images, which are difficult to store on small devices, expensive to download, and cannot be searched. The problem is that OCR is not perfect.
Use reCAPTCHA on Your Site!reCAPTCHA helps prevent automated abuse of your site (such as comment spam or bogus registrations) by using a CAPTCHA to ensure that only humans perform certain actions.
- It's Free! Yep, reCAPTCHA is free.
- It's Useful. Why waste the effort of your users? reCAPTCHA helps to digitize books.
- It's Accessible. reCAPTCHA has an audio test that allows blind people to freely navigate your site.
- It's Secure. Most other CAPTCHA implementations can be easily broken.
- It's Popular. Over 100,000 sites use reCAPTCHA, including household names like Facebook, Ticketmaster, and Craigslist.
- It's Easy. reCAPTCHA is a Web service. As such, adopting it is as simple as adding a few lines of code on your site. For many applications and programming languages such as Wordpress and PHP we also have easy-to-install plugins available. We generate and check the distorted images, so you don't need to run costly image generation programs.