CAPTCHA, short for “Completely Automated Public Turing test to tell Computers and Humans Apart”, is a computer test designed to determine whether a system is being used by a human or a machine. This method is often used on the Internet to prevent bots from accessing various online services, including automatic account registration, file downloading, and mass mailings.

Traditional CAPTCHA forms may involve asking you to enter text from distorted images of letters and numbers, or to select specific objects in pictures, such as bridges, motorcycles, or crosswalks. Over time, CAPTCHAs have become more complex, and some of them have become so complex that even humans find them difficult to solve.

Bots that try to imitate humans are getting smarter and evolving – aggregate DataDome customer data shows that 50% of the “users” who pass them on are actually bots. Therefore, CAPTCHA developers resort to increasingly complex hints each time to deter hackers and spammers.

However, a recent study from Stanford University found that using captcha reduces sales conversion by up to 40%, discouraging potential buyers due to frustration. And it’s not just about complex hints – even simple ones are difficult for users with visual impairments, for example.

Alternatives to CAPTCHA already exist, but have probably not gained the same popularity. There are so-called invisible checks – tools that collect thousands of signals in the background, for example related to the device, not the user himself, or detect proxy servers used by scammers. It’s much harder for bots to adapt and learn, given that the code works behind the scenes and doesn’t offer the robot an obvious test.

Here again, another study from Forrester found that while users may experience frustration when faced with a CAPTCHA, they also feel safer when taking the test.