Various CAPTCHA options

Have you ever had to type a combination of letters or numbers on a website to verify if you are human? Then you are familiar with what a CAPTCHA is. The acronym CAPTCHA stands for Completely Automated Public Turing Test to tell Computers and humans. They help differentiate malicious users and actual human site visitors. Therefore, they protect tour content, being the core driver for the website traffic. Since cybercriminals use automated bots (Computers), CAPTCHA attempts to inhibit their access to your website since they cannot solve them. Since computers have grown more intelligent in this time and age, the bots try to evade or bypass the CAPTCHA altogether. To allow for broad usage, CAPTCHA can come in different options. Below are the various CAPTCHA options that you are likely to encounter in your surfing.

Word Problem

There are different variations of this type of CAPTCHA, but they all have the following two parts; a sequence of characters and a text box. To prove that you are human, you need to follow the directions of the test carefully. The test might be entering the last word in a list, retyping the sequence of letters that are not in order, or entering which color is used to display the word(s). It offers an excellent option for the visually impaired and those who have problems with other CAPTCHA options. The major limitation is that bots can solve that Word Problem CAPTCHA because they are getting more intelligent nowadays.

Arithmetic Problems

This is among the most popular options for CAPTCHA. It displays a mathematical problem on a website with a text box for you to write the answer next to it. Solve and answer a mathematical problem like ‘1+9’. This is easy in the eyes of a human being, but it can be hard for a robot to solve and key in the answer. That makes mathematical problems secure and used by many. Because it is simple and easy to read, a user can quickly solve it and continue surfing the website. Therefore, this CAPTCHA option enhances the website’s security while being effective for the user. Compared to other types of CAPTCHA, it is not very sophisticated.

Time-based CAPTCHA

This type of CAPTCHA keeps the record of the time a user takes to fill out a form. Bots fill the form in split seconds, whereas a human takes a bit of time. Its merit is how it differentiates a human from a bot based on time. Conversely, requiring a person to fill out their information on a form whenever they want to comment, message, or perform a task can be both time-consuming and frustrating. Another disadvantage is that nowadays, bots use a ‘low and slow approach to ensure they do not detect their activities online.

Identification of Pictures

In this option for CAPTCHA, there are different types/ forms of image tests. It can ask you to name an image, identify an odd image out of a set, or differentiate an image from a set of pictures. By taking advantage of a bot’s weakness in vision, this CAPTCHA effectively keeps them away from your website. You do not read any text in this CAPTCHA option, but you identify an idea or object within an image. They may also require you to choose an object from an array of objects. It relieves you of a great deal of time that you’d otherwise have used to solve them, and you can deal with over one test at a time if the first one fails.

Signing in To Social Media

It is foolproof to ask that users sign in using their Instagram, Twitter, Facebook, or any other social media account. This form of CAPTCHA verifies a user without them entering any data. This CAPTCHA option is practical and helpful since bots do not have social media accounts. Therefore, the bots cannot access the website’s content unless the more intelligent ones bypass the CAPTCHA. The major drawback is that many users, and most possibly you, are not comfortable sharing their personal information for its security. Because they use one click to log in using a social media account, users log in to a website swiftly compared to when they have to enter all their information.

Honeypot CAPTCHA

In this CAPTCHA option, there are hidden files on the screen. Honeypot CAPTCHA tricks the bots into filling the hidden files because they can see them, unlike humans. When a user fills the files, the website knows that the user is most likely a bot. Because human users do not know its existence, the Honeypot CAPTCHA is helpful because it protects the user experience from annoying games and entering a lot of information. You have used a website having a honeypot CAPTCHA without knowing.

Some bots are intelligent enough to realize they are being tricked. To achieve this, a developer needs to add a hidden field with any name and use the set’ display: none’ using CSS. It will hide it from human users. This CAPTCHA option is unique from the others and uses a unique approach to keep the bots off your site.


This CAPTCHA option was developed by Google in 2014 and has already broken into the internet. It uses behavioral analysis to separate a human user from a bot. It presents you with a simple task like clicking ‘I am not a robot’. When used on an application or a phone, one has to click a box containing I am not a robot using a finger. If you click the box at the center, then you are interpreted to be a bot. Because bots are very methodical, it is easy to determine them by their behavior, unlike humans. Thanks to Google, this method has been very effective and accurate in stopping and determining bots, respectively. If a user fails this test, it requests them to type a combination of letters and/or numbers.

Confident CAPTCHA

It is an image-based CAPTCHA method. The user follows some kind of direction with something to do with images. The most common example of this CAPTCHA option is ‘click on images containing…‘ from a set of several images. They may ask you to click the images containing traffic signs, fire hydrants, and storefronts. There is a 96% chance of success in this form of CAPTCHA, although it can frustrate a user if they did not perform the task correctly the first time. It is because they will have to go through the same process repeatedly until they get it right. This CAPTCHA option is beneficial as someone can monetize it through advertising.

Other CAPTCHA options include sweet CAPTCHA and invisible reCAPTCHA.


CAPTCHAs can exist in different forms and there are a lot of CAPTCHA and reCAPTCHA alternatives. It is upon the website owner to decide what CAPTCHA option to use for your website. The bottom line is, select a CAPTCHA that does not discourage the users because this can be detrimental to your business. Ensure that you use at least one option to prevent bots from generating fake traffic on your website and performing various attacks on your online infrastructure.