What is Captcha? Why We Use the Captcha Code

What is Captcha Why We Use the Captcha Code

On the Internet, you too may have been bothered many times about what CAPTCHA are which most people like us have done. While registering in a website, creating an ID or commenting on a blog, we encounter CAPTCHA CODE.

In front of us, some crooks numbers and alphabets comes to write or to select the image according to the question asked.

Many times you may have wondered what CAPTCHA is and why it is needed. What is CAPTCHA’s work and many other questions will definitely come to your mind. Today you will get all the information related to CAPTCHA through this article.

In this article you are explained in detail what is CAPTCHA, why it is used, how many types are there and how to solve CAPTCHA etc. If you do not know about CAPTCHA, then this information can prove very useful for you.


CAPTCHA’s full form is “Completely Automated Public Turing Test to tell computers and Humans Apart”. Captcha is also known as Captcha Code. The work of both is the same.

This is such a device, which is like a security system, with the help of this we find out that the person writing or the machine or robot.

Basically it explains the difference between machine and human being. Writing CAPTCHA CODE is not an easy task for any robot. When we sign-up on a website, create an account or comment on a blog, then we have to write Captcha Code.

Where and how we use the CAPTCHA CODE    

It is used for security, which only humans can solve, no robot or machine can solve it. Their design is made in such a manner that they prevent spammers and hackers from going to the restricted area so that important information on the website can be protected.

They are used when registering on a website, creating an account, or while commenting on a website.

Captcha is not only shown in images. Apart from images, you are also used to write some crossword letters, arithmetic, computation and writing them properly, while most of the time, you are given half-and-half letters and some numbers with which to solve.

Who invented CAPTCHA

The term Captcha was introduced in 2003 by Luis von Ahn, Manuel Blum, Nicholas J. Hopper, and John Langford. The most common form of Captcha was first invented in 1997 by two groups doing parallel work.

In this form of Captcha one needs to evaluate correctly and enter the sequence of letters or numbers that appear in the distorted image displayed on their screen.

Because the test is administered by a computer, unlike the standard Turing test administered by humans, Captcha is sometimes described as a reverse Turing test.

Types of Captcha

Many times we have to face different types of Captcha, which is different from the part of every website. There are many types of Captcha Code.

  • Image Recognition Based:  Captcha codes which are image-based show some similar-looking images which are also given a name above.
  • In which you have to find and select the picture associated with the given name, after that you get an entry on the website.
  • Math Solving Captcha:   A popular form of Captcha is a simple math problem that is added to any site. For example, a user may have to solve an answer to a math problem like “4 + 6” or “8+2”.
  • Text Recognotion Based:  Such Captcha which are puzzles and these are the text base, the user has to identify the text to solve it and in Captcha you have to solve it by alphabet type. After which you can enter on that website.
  • 3-D Captcha:  Seeing 3-D image and would recognize the numbers and alphabets in it and write them.
  • Audio Recognition Based:  In this, the user has to listen to an audio and fill it in the box.
  • Social Authentication:   It is mainly used in social media websites like Facebook etc. Its puzzle is based on your friend’s profile photo, only after identifying it; you get an entry on the website.
  • Logic Based Captcha:  This type of puzzle has logic based questions, and only after answering them can you get an entry in that website.

These are some types of Captcha, which you must have solved somewhere. But in order to solve all this, users do not waste much time, so Google launched a Captcha Code in which you do not need to write, identify anything.

Google improved the re-Captcha in 2009 to create no Captcha re-Captcha. In this Captcha, you have to click in a box, after which Google’s Algorithm automatically detects whether you are a human or a robot.

How to solve a Captcha Code

Captcha is easy to solve. But it is difficult for Robot. You must have seen that there are many types of Captcha Code and you have to solve them accordingly. If there is a Text Base Captcha, then you have to write it in the Identified Text Box. It is a bit difficult to read.

Because many time the 3-D effect is either scratched on it, so that the machine cannot read. You will have some difficulty but you can still solve.

If you are given a Math problem, it has to be solved and written as an answer. Many times you also have to select the image. Can proceed as instructed and solve it correctly. If you are unable to do any kind of reading, you can solve the new code by doing “re-Captcha”.

Advantages of Captcha

Ever since the implementation of Captcha Code, it has been used much later. Captcha Code protects our websites and blogs from hackers etc., due to which bots are not able to enter our website. Some advantages are as follows.

  • Using Captcha Code will stop spam comments on your blog.
  • It is also used because only humans can solve it, not robots or machines.
  • This protects our E-Mail address from scrappers.
  • It is also used to protect the website from Dictionary Attack.
  • Provide security to the website security.
  • Creates online poll.

Disadvantages of Captcha

While everything has some benefit, it also has some disadvantages, let us tell you its disadvantages.

  • It is designed to understand humans, but sometimes robots do not even humans understand it.
  • In many browsers some technical problems arise because of Captcha Codes.
  • It takes a lot of time to create an id; because of this people go only by visiting the blog, not even creating an account.

What is the future of Captcha Code

Nowadays the use of Captcha has become much more, slowly, Captcha is also becoming difficult, because nowadays many new software solve simple Captcha very easily. Therefore the difficulty of Captcha Code has been increased so that they cannot be cracked easily.


In this post, I have tried to give you more and more information about Captcha, also told you its status from the beginning till now.

Captcha is necessary to protect your site. If you have any suggestions or questions, you can ask in the comments.

Also Read: How To Track Android Phones With Hidden Spyware?

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