How to solver Captcha With Python and NextCaptcha
Tags: recaptcha, bypasscaptcha, python
Published: 2024-03-19 04:35:35


CAPTCHA, short for Completely Automated Public Turing Test to Tell Computers and Humans Apart, has long been a contentious element in user interfaces. It aims to thwart automated bots but often proves to be an annoyance for users. Over time, CAPTCHA tests have become more complex, yet methods for bypassing them have evolved as well. In this tutorial, we'll explore how to circumvent CAPTCHA using Python and NextCaptcha. This tool allows developers to automate solving CAPTCHA challenges, enhancing user experiences while maintaining security against bots and scripts.

## **What are CAPTCHAs?**

CAPTCHA stands for "Completely Automated Public Turing test to tell Computers and Humans Apart." It is a type of challenge-response test used in computing to determine whether or not the user is human. CAPTCHAs are typically used to prevent automated programs, often referred to as bots or spambots, from performing certain actions on websites, such as creating accounts, submitting forms, or accessing restricted content.

CAPTCHAs usually involve presenting the user with a task that is easy for humans to solve but difficult for automated programs to complete accurately. This task could be identifying distorted letters or numbers, recognizing objects in images, solving puzzles, or performing other simple tasks.

The purpose of CAPTCHAs is to ensure that interactions on websites are conducted by real human users rather than automated scripts or bots, thus helping to prevent spam, fraud, and other malicious activities.

## CAPTCHA's Shortcoming

While CAPTCHAs serve the purpose of distinguishing humans from bots, they also come with several downsides:

1. Accessibility Issues: CAPTCHAs can pose significant challenges for users with disabilities, particularly those with visual impairments who may have difficulty deciphering distorted text or identifying objects in images. This can result in excluding certain individuals from accessing or interacting with websites.
2. User Frustration: CAPTCHAs can be frustrating for users, especially when they are overly complex or difficult to solve. This frustration can lead to a poor user experience and may deter users from engaging with a website or completing desired actions.
3. Effectiveness Decline: As CAPTCHA-solving technology advances, some bots and automated scripts have become more adept at circumventing CAPTCHA challenges. This diminishes the effectiveness of CAPTCHAs in preventing automated activities and spam.
4. Impact on Conversion Rates: Overly intrusive or cumbersome CAPTCHAs can negatively impact conversion rates on websites, such as e-commerce platforms or registration forms. Users may abandon the process altogether if they find the CAPTCHA too burdensome, resulting in lost potential customers or users.
5. Maintenance Overhead: Websites that implement CAPTCHAs need to continuously monitor and update their CAPTCHA mechanisms to stay ahead of evolving bot technologies. This incurs maintenance overhead and additional costs for website operators.
6. Security Risks: While CAPTCHAs are designed to enhance security by distinguishing humans from bots, they can also introduce security risks if implemented incorrectly. For example, poorly designed CAPTCHAs or third-party CAPTCHA services may inadvertently expose websites to vulnerabilities or privacy breaches.

Overall, while CAPTCHAs are a commonly used tool for combating automated activities and spam, they come with trade-offs that website operators must consider carefully to balance security, usability, and accessibility.

## **What is NextCaptcha**

[NextCaptcha](https://nextcaptcha.com/) is efficient and reliable captcha solver solution. NextCaptcha employs two primary API endpoints to address a range of CAPTCHA styles. The initial request transmits the necessary data for CAPTCHA resolution and yields either a request ID or a base64-encoded image for image CAPTCHAs. Upon acquiring the request ID, subsequent requests are made to the designated endpoint, which is periodically queried until the solution is provided.

## **Setup**

We need to sign up on [NextCaptcha](https://nextcaptcha.com/)'s platform to create an API Key for making requests.

- Register


![NextCaptcha Register](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/4965g1bdi7ft8trzovbs.png)

- **Copy API Key**

As shown below, we now have access to the API Key on our dashboard, which we will utilize later in this tutorial.


![NextCaptcha dashboard api key](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/tvkpp2l2q6g66s4otqal.png)

### Step 1 - Create project and initialize

Create project and install nextcaptcha-python sdk

```bash
mkdir solver-recaptcha-python-demo
cd solver-recaptcha-python-demo
pip install nextcaptcha-python
```

### Step 2 - Create a file

Create entry file

```bash
touch index.py
```

### Step 3 - Demo Site

We'll use official demo website[] to see whether we can bypass the captcha on their submit form.

First, we need to obtain the site/captcha key, which will be incorporated into our request body when sending a request from our application. Let's navigate to the Element tab, depicted below, to copy the key.


![find the reCaptcha sitekey](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/1kkrb7zk18qwgdduz6tw.png)

or you can input this code in console to get the element attr

```jsx
$('[data-sitekey]')
```

### Step 4 - Demo

We successfully retrieved the site key in Step 3, so let's head over to our application to submit the infomation and bypass the captcha, which is what we set out to accomplish in this article.

In [index.py](http://index.py/), let's create a function with the required data to request NextCaptcha to bypass captcha on user submit action as shown in the snippet below:

```python
from nextcaptcha import NextCaptchaAPI

// Get access to solver by passing your API key
CLIENT_KEY = "YOUR_CLIENT_KEY"
WEBSITE_URL = "https://www.google.com/recaptcha/api2/demo"
WEBSITE_KEY = "WEBSITE_KEY"

def main():

    api = NextCaptchaAPI(client_key=CLIENT_KEY)
    result = api.recaptchav2(website_url=WEBSITE_URL, website_key=WEBSITE_KEY)

    if result["status"] == "ready":
        print(f"reCAPTCHA solved: {result['solution']}")

        response = requests.post("https://www.google.com/recaptcha/api2/demo", data={
            "g-recaptcha-response": result['solution']['gRecaptchaResponse']
        })
        print(f"submit bypass: {response.text}") # it will show Verification Success... Hooray!

    else:
        print(f"Failed to solve reCAPTCHA: {result['error']}")

if __name__ == "__main__":
    main()
```

In the snippet above

- We get access to the solver by passing our API key
- We send the captcha solution and other data to the server using pythons sdk
- We then log the response and wait for NextCaptcha

To run this

```bash
python index.py
```

It will return the solution almost immediately then we could sumit with the return gRecaptchaResponse.

Voila 🥳 We successfully bypassed the captcha during the registration, and now we have a token to log in, as shown above. Let us proceed to submit.

### **Conclusion**

In this article, we've effectively learned how to bypass CAPTCHA and successfully log in, a method applicable to any website employing CAPTCHA security measures.

### **Resources**

[nextcaptcha](https://nextcaptcha.com/)

[nextcaptcha-python](https://github.com/nextcaptcha/nextcaptcha-python)