What is a CAPTCHA?

CAPTCHA refers to a completely automated public Turing test that is useful to differentiate between computers and humans. CAPTCHA is mainly used to determine whether the website user is real or a spam robot. 

CAPTCHA is essentially an anti-spam tool that asks users to prove they are humans and not spam software. They are designed in various ways to perform this function. Some ask you to solve a simple math problem, while others require you to type a series of numbers and letters from an image provided. 

CAPTCHAs help protect the online website’s integrity by stopping hacker’s activities of using robots to send repeated false responses. 

Reasons Why Websites Use a CAPTCHA?

Any websites that want to restrict the usage of their site by bots make use of CAPTCHA. 

Some of the specific uses of CAPTCHA by websites are as follows:

  • Limiting Registration for various Services

CAPTCHAs can be used by various services to prevent bots from spamming their registration systems or creating fake accounts. Businesses can prevent wastage of their service resources by restricting account creation, thereby reducing opportunities for fraud.

  •  Maintaining Poll Accuracy 

CAPTCHAs maintain poll accuracy by ensuring that each vote is entered by humans and not by any spam robots. This process increases the voting time of each vote and discourages multiple votes. However, the overall number of votes are not limited. 

  •  Prevent False Comments 

The spamming of contact forms, review sites and message boards by bots can be prevented using CAPTCHA. The extra step used by them providing users to retype or distorted letters or solve a problem plays a crucial role in reducing online harassment through inconvenience. 

  •  Prevent Ticket Inflation 

Ticketing systems can use CAPTCHA significantly to limit the purchase of a huge number of tickets for resale. They are also helpful to prevent false registrations of free events like gigs or concerts.

How CAPTCHAs Work to Protect your Website 

CAPTCHAs work on providing information to any user to interpret it. They  provide users with distorted and overlapping numbers or letters that have to be filled and submitted in the form field by the user. It is difficult for bots to interpret the text due to distortion and overlapping, thereby preventing their access to the website until the characters are verified. 

CAPTCHA mainly rely on human’s ability to recognize and generalize patterns based on their experience. The limitation of bots to be able to follow only a set patterns  makes it difficult for bots to exactly guess the right combination correctly. 

However, recently bots that can use Machine Learning(ML) techniques are being developed, making them even better by improving their ability to identify CAPTCHAs, including algorithms trained in recognizing patterns. This resulted in the development of newer CAPTCHA methods that provide users with more complicated tests. For instance, Google reCAPTCHA is the new CAPTCHA method that requires the user to click on a specific area and wait until the timer runs out.

Benefits of using the CAPTCHA 

CAPTCHAs prevent hackers from abusing online services with their ability to block robot software from submitting fake online requests. 

The benefits of using CAPTCHA include: 

  • Preventing cybercriminals from spamming news content pages or blogs with redirecting links to other websites
  •  Stopping hackers from signing up for multiple email accounts, which are later used for spamming purposes.
  •  Stop force attacks on online accounts by hackers who try to log in using several different passwords repeatedly.
  •  Preventing ticket touts from the bulk purchase of tickets for gigs and shows.
  •  Protecting the integrity of the website by stopping hackers from using robots to send repeated false responses.

CAPTCHA is considered an anti-spam tool that aims to protect your website from spammers. The benefits mentioned above help businesses secure their website from spam attacks, thereby increasing the website’s integrity. 


The CAPTCHA technology is used by businesses to authenticate a real person is accessing their web content and not a spam robot. The ultimate goal is to block spammers and bots that try to sign up for website access automatically or to get access to the content of blogs and forums. 

CAPTCHAs tend to block automated systems which are unable to read distorted letters in the graphic provided. Therefore, businesses willing to protect their website content and access from spammers need to use the CAPTCHA tool to make the website more safe and secure.