What is the Captcha Code and what is it for?

Captcha Code and what is it for

You will surely come across several of these security actions on a daily basis while surfing the net. But if you are here it is because you want to really understand what captcha code is and how this element works.

This protection system, established by most websites not long ago, has some drawbacks for the end user, but many benefits for the network as a whole. Stay and you will see!

In this article you will learn what a captcha code is, its most widespread uses and some example codes so that you can see how it is used in real practice. We started!

What is Captcha Code?

Captcha code is, basically, an online security system to be able to verify the type of user that is accessing said information, form or another type of access. Through this recognition system, it is possible to distinguish between a human and an automated robot whose intention is to hack or sabotage a specific web page.

Normally, it is usually implemented in forms on web pages and in other elements that involve the delivery of data from an external agent on the website in question.

There are various types of captcha codes available and these are constantly evolving and developing to combat today’s increasingly effective cyberhacking techniques.

Its name derives from the English language and refers to the acronym Completely Automated Public Turing  test to tell Computers and Humans Apart. Yes, there is nothing.

Perhaps you have recognized among this name the great Alan Turing, inventor of the Enigma machine that allowed to decipher secret codes of the German side in World War II or the famous Turing test.

Also, in reality, the purpose is similar to the homonymous test. Determine the level of “intelligence” of the other party.

What is the Captcha Code used for?

The captcha code has a main function: to differentiate Internet users between human users and spam bots when submitting a form on a website, accessing a user’s profile or other types of actions related to security and access to certain online data.

If you do not want clear what SPAM is and above all, how you can avoid Spam on your website, access the link that I have left you previously. Network security is not an irrelevant topic and it can save you a lot of trouble in the future.

Although its use is spreading beyond this aforementioned function. At present, it is possible to find this type of code in sectors such as:

  • Text transcription – Contributing to the digitization of book catalogs.
  • Identification – Reporting what object it is for Google Street View images, for example.

How does Captcha work?

It is worth mentioning that this type of captcha codes does not have a unique way of proceeding, since, depending on the type of it, you will have to complete one task or another totally different to verify your identity.

The operating system is the sample of a small “riddle” to the user to verify that, if he is able to solve it, it is a real person. And for this, it is normal to resort to small questions with mathematical calculations [addition, subtraction, multiplication …], writing semi-hidden codes between the displayed images or the selection of certain elements that have a logical relationship between them.

In addition to other ways such as:

Also this is one of the key elements of today. In its origin, the name comes from the fact that, only with the introduction of the code displayed in the image, the identity was verified.

But the evolution of automatic bots has forced the cybersecurity industry to resort to elements that are more complex to recognize by a computerized system, such as this type of images and sound elements.

Most used Captcha Code examples

Spambots are gaining ground in this field, so the captcha code that you are going to find today will certainly present a greater difficulty than what you could find a few years ago.

And this leads to confusion on the part of users and a slowdown in the tasks to be carried out. Surely you have also had to repeat the captcha several times because you were not able to determine exactly what sign was shown in the image.

However, I leave you with some captcha examples currently used and that work on millions of websites.

Mathematical operations

For example, in order to continue with the task undertaken, the user must successfully solve small mathematical operations. Neither is anything that presents too much difficulty, most are usually simple sums of two factors.


example captcha mathematical calculation

Hidden Codes

It is the original and most common format to find on the net. The task is to be able to write the character string that is hidden in the displayed image. And in some cases it is not easy!

hidden captcha codes

Captcha and reCaptcha code differences

Both are often known as captcha codes, but there are variations that need clarification.

ReCaptcha is basically the technological evolution of the original Captcha. In addition to adding much more complexity and variety to your puzzles, it now also detects user behavior on a website and the likelihood that it is caused by a human or a bot.

Yes, the third generation of reCaptcha V3, give each user a different score [ranges from 0.0 to 1.0] depending on how they interact with the website; mouse movement, web time spent in each section or the number of clicks made on it.

By default, reCaptcha v3 requires a score of 0.5 points to be able to verify the code with just one click by marking the checkbox. In case the score detected by the system is lower, it will be when it shows you a puzzle to solve.

So now you know, if they show you many of these reCaptcha, it is because your behavior is “suspicious” in the face of the system.

Finally, it also allows webmasters and website owners to access their users’ scores in order to verify the level of real human traffic they are receiving, as well as the possibility of implementing other extra authentication systems for users with very low scores. Such as email verification.