ABSTRACT. CAPTCHA is a tool for recognizing a robot when trying to register, or filling out any other form on the site. CAPTCHA stands for - Completely Automated Public Turing test to recognize computer among the users. In this article we analyze Captcha and NoCaptcha. It is shown that for an ordinary user of the site NoCAPTCHA is more convenient, and intuitive than CAPTCHA. Considering the fact that the main problem for any CAPTCHA is its implementation, we show that the mechanism of protection from bots in any CAPTCHA is based on the actions of an ordinary user, and in this situation the user acts as a filter, what is not entirely fair, moreover, the latter conducts for the system work, for which he certainly is not paid. We consider that developers definitely need to consider the needs, and what is more important, the capabilities of average users. Based on this, to construct first of all convenient, and effective defense mechanism. Convenience of consumption is a priority for any project, and the loss of potential users due to obstacles in the form of a strong complication of the registration process, which is currently quite relevant - is a losing option for any project.