Spam is annoying. But so are captcha codes and robot challenges that hinder the experience of your website visitors. NullCaptcha is spam-prevention technology that eliminates the need for annoying security captcha codes and spam challenges. NullCaptcha is a RESTful service that works with any website and any platform to implement spam protection on web forms easily. NullCaptcha is free to use for low-traffic websites, and offers low-pricing and customized pricing options for high-traffic websites and web applications.