What is a Captcha And How To Bypass CAPTCHAs
Tags: productivity, webdev, performance, captcha
Published: 2022-02-14 09:58:34


Have you ever come across a checkbox asking you to confirm if you are not a robot followed by a visual test asking you to select images of traffic lights or something of that nature? I'm sure you have, especially if you have been using the internet frequently this past few years. This annoying test is known as a CAPTCHA.

![An example of a CAPTCHA test - NoCAPTCHA ReCAPTCHA](https://res.cloudinary.com/denkuysrh/image/upload/v1699795926/Article%20Images/Timonwa%27s%20Notes/what%20is%20a%20captcha/48CAkrd_O_sik9za.gif)

<figcaption>An example of a CAPTCHA test - NoCAPTCHA ReCAPTCHA</figcaption>

You usually would have to pass a CAPTCHA test before you can have access to certain parts of a website, especially if you want to make a purchase, fill out a form, or subscribe to a service.

It is usually time-consuming and annoying for users often making us wish we had a way we could automatically solve CAPTCHAs. But for companies and service providers, it is a safe way for them to secure their websites and data.

In this note, I will be explaining what CAPTCHAs are, the types, their usefulness, and their difficulties. I will also be telling you about a CAPTCHA Solver service you can use to bypass it.  For a more detailed guide on how to overcome CAPTCHA challenges, you can check out my article on [Using Captcha Solvers to Improve Web Accessibility & Work Productivity](https://timonwa.com/blog/using-captcha-solvers-to-improve-web-accessibility-work-productivity).

![lady saying 'stay tuned'](https://res.cloudinary.com/denkuysrh/image/upload/v1699795943/Article%20Images/Timonwa%27s%20Notes/what%20is%20a%20captcha/Wc9ut3unW_u71pou.gif)

## So What is a CAPTCHA?

[CAPTCHA](http://www.captcha.net/) stands for Completely Automated Public Turing test to tell Computers and Humans Apart, a term coined by Luis von Ahn, Manuel Blum, Nicholas J. Hopper, and John Langford in 2003.

It is a challenge-response test used on websites to know if it is a human or a computer/bot that is trying to gain access to areas of restrictions on its website.

![A robot saying "I'm not a robot dumbass I'm alive"](https://res.cloudinary.com/denkuysrh/image/upload/v1699795962/Article%20Images/Timonwa%27s%20Notes/what%20is%20a%20captcha/Z5BFqLVP3_veoag1.gif)

The tests are usually visual challenges that are difficult for computers to solve but easy for humans. For example, clicking in a specific area or identifying stretched letters or numbers.

Computers do not usually have the sophistication that human beings have when it comes to processing visual data. So where we can look at an image and pick out patterns easily, a computer cannot.

![A robot trying to twist a door numb but twisting the air instead](https://res.cloudinary.com/denkuysrh/image/upload/v1699795978/Article%20Images/Timonwa%27s%20Notes/what%20is%20a%20captcha/a1ojGSGvt_xji4rf.gif)

## What are CAPTCHAs Used for?

Any website that desires to restrict usage and access of their services or data uses CAPTCHA to do so. Examples of such restrictions include:

- Ensuring people don't mess with poll accuracy by using a bot for voting or voting multiple times.
- Prevent bots from spamming message boards, contact forms, or review sites with false comments.
- Prevent people from buying lots of tickets to an event for resale or fake registrations for the event.
- Prevent people/bots from making multiple fake accounts on websites.

## How Do CAPTCHAs Work?

CAPTCHAs work by providing information to a user for interpretation. It could be overlapping letters and numbers that a user then has to submit via a form field or clicking in a specific area and waiting until a timer runs out.

## Types of CAPTCHAs.

There are different types of CAPTCHAs and they can be identified as either Text-based, Image-based, or Audio-based.

### Text-based CAPTCHA

They make use of words, phrases, or combinations of random letters and numbers which can also be a combination of small and capital letters.

![A text-based CAPTCHA](https://res.cloudinary.com/denkuysrh/image/upload/v1699796003/Article%20Images/Timonwa%27s%20Notes/what%20is%20a%20captcha/CdwNVsCmG_ys31pt.png)

<figcaption>An example of a text-based CAPTCHA</figcaption>

### Image-based CAPTCHA

They use photos of animals, shapes, or scenes which are supposed to be recognized easily by humans. The users are required to select images matching a theme or identify images that don't fit.

![An image-based CAPTCHA - Select all images with taxis](https://res.cloudinary.com/denkuysrh/image/upload/v1699796038/Article%20Images/Timonwa%27s%20Notes/what%20is%20a%20captcha/I42bnLnpw_mxnvzx.jpg)

<figcaption>
  An example of an image-based CAPTCHA - Select all images with taxis
</figcaption>

### Audio-based CAPTCHA

They use recorded audio of words or phrases which the user has to listen to and give back as input.

![An audio-based CAPTCHA](https://res.cloudinary.com/denkuysrh/image/upload/v1699796054/Article%20Images/Timonwa%27s%20Notes/what%20is%20a%20captcha/k6hv-CNshJ_dums3z.png)

<figcaption>An example of an audio-based CAPTCHA</figcaption>

### No CAPTCHA reCAPTCHA

This asks the user to click on a box stating I am not a robot. It captures mouse movements to determine if a user is human or not.

![A No CAPTCHA reCAPTCHA](https://res.cloudinary.com/denkuysrh/image/upload/v1699796072/Article%20Images/Timonwa%27s%20Notes/what%20is%20a%20captcha/kYsu8b6Ow_kr07zr.png)

<figcaption>An example of a No CAPTCHA reCAPTCHA</figcaption>

### Math or Word Problems

This asks the users to solve a simple mathematical problem such as "5+4" or "8-3" or to type the word missing in a sentence or complete a sequence of several related terms.

![A math-based CAPTCHA](https://res.cloudinary.com/denkuysrh/image/upload/v1699796093/Article%20Images/Timonwa%27s%20Notes/what%20is%20a%20captcha/HN2WfezkH_notlbj.png)

<figcaption>An example of a math-based CAPTCHA</figcaption>

## Difficulties of using CAPTCHAs

Although CAPTCHAs are effective to most bots, there are some drawbacks to using them:

- They can be frustrating for users to use.
- They can be difficult to understand by a certain audience.
- Not all browsers support them.
- Some CAPTCHAs are not accessible to screen readers.
- They can be time-consuming.
- They are not entirely foolproof.

We have now come to the juicy part… bypassing CAPTCHAs.

![A man wiggling his shoulders and smiling](https://res.cloudinary.com/denkuysrh/image/upload/v1699796108/Article%20Images/Timonwa%27s%20Notes/what%20is%20a%20captcha/SlD9Hwhao_ncglmu.gif)

## How to bypass CAPTCHAs

You might be wondering how you can bypass CAPTCHAs. Well, there are several ways you can do that. One of them is by using a CAPTCHA solving service.

CAPTCHA solving services are services that help you bypass CAPTCHAs. They are usually powered by humans who solve the CAPTCHAs for you or AI that can solve the CAPTCHAs.

These services help you bypass CAPTCHAs by sending the CAPTCHA challenge to their servers, which then sends it to a human worker or an AI to solve it and send the answer back to you. They can help you bypass text-based CAPTCHAs, image-based CAPTCHAs, and audio-based CAPTCHAs, and more.

There are several CAPTCHA solving services out there, like [2Captcha](https://2Captcha.com) which we will be talking about in this article, [Capsolver](https://www.capsolver.com/), Anti-CAPTCHA, and Death by CAPTCHA.

## Bypassing CAPTCHA using 2Captcha

I recently came across the CAPTCHA solving software called [2Captcha](https://2Captcha.com). It is a Human-powered CAPTCHA-solving service, which means that each CAPTCHA is solved in real-time by human intelligence and not by computer or robot thus providing a high level of accuracy.

![2Captcha - Human-powered CAPTCHA-solving service](https://res.cloudinary.com/denkuysrh/image/upload/v1699796125/Article%20Images/Timonwa%27s%20Notes/what%20is%20a%20captcha/l3bYALXhX_h74eid.jpg)

<figcaption>2Captcha - Human-powered CAPTCHA-solving service</figcaption>

2Captcha can recognize different types of CAPTCHA (remember the examples I gave above?) and Its API is available for most programming languages. Their average response time is less than 12 seconds and their service is inexpensive starting from just $0.50 for 1000 solved CAPTCHAs. And that's a lot compared to what you are paying for.

There are two ways you can use it, which is by either integrating their API if you are a developer or using their browser [extension](https://chrome.google.com/webstore/detail/2Captcha-solver/ifibfemgeogfhoebkmokieepdoobkbpo?hl=en). if you don't want to write code. Ps, you can also earn additional income on 2Captcha by solving CAPTCHAs, after all, it IS powered by humans.

### So How Exactly does 2Captcha work?

Since 2Captcha has workers who are willing and waiting to solve CAPTCHAs, a customer wanting to solve a CAPTCHA in real-time requests with the CAPTCHA challenge via their API directly or through their browser extension to the 2Captcha server which then delivers the CAPTCHAs from the customer to their worker. Once the CAPTCHA is solved, 2Captcha servers deliver the answer back to the customer. It's that easy and all these happen in seconds.

The customer pays for the service and the worker also gets paid for solving the CAPTCHA. It's a win-win for everybody.

## Conclusion

And that's it on CAPTCHAs. I hope you enjoyed the note. Remember CAPTCHA helps to keep the bad guys out and the good guys in. But sometimes they are very annoying, that's why services like 2Captcha help us automate the process.

Other services like Capsolver also help us bypass CAPTCHAs using AI and machine learning. So if you are a developer or a user who wants to bypass CAPTCHAs, you can use any of these services.

If you want to explore the best CAPTCHA solvers specifically tailored for Google Chrome, check out this comparison guide [here](https://slashdot.org/software/captcha-solvers/for-google-chrome/).

If you enjoyed this note, please share it with your friends and colleagues. Till next time guys.

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<figcaption><a href="https://giphy.com/gifs/wave-hello-hi-I5bk7sUToEBxe">via GIPHY</a></figcaption>
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## Explore More

Discover more insights and tutorials on my blog:
- Dive into [JavaScript Projects for Beginners](https://timonwa.com/blog/series/javascript-projects-for-beginners) and enhance your coding skills with practical projects.
- Learn to seamlessly integrate [Sender.net with a React Form](https://timonwa.com/blog/integrate-sender-with-react-form) for free email collection and delivery.
- Unlock enhanced web accessibility and productivity with our guide on [Using Captcha Solvers](https://timonwa.com/blog/using-captcha-solvers-to-improve-web-accessibility-work-productivity).