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reCAPTCHA V3

reCAPTCHA V3 is Google's latest CAPTCHA system. Unlike earlier versions, it requires no user interaction—no checkboxes or image challenges. Instead, it runs silently in the background and assigns a "humanity score" between 0.1 (likely bot) and 0.9 (likely human). Websites use this score to decide whether to allow or block a request.

Overview​

reCAPTCHA V3 is fundamentally different from V2:

  • No visible challenge - Runs completely invisible to the user
  • Assigns a score - Not a binary pass/fail, but a probability score (0.1 to 0.9)
  • Must be submitted in backend - The token is sent to the server for verification
  • Action-based - Different actions (login, submit, etc.) can have different score thresholds
  • CaptchaAI provides score of 0.3 - Accepted by most websites
reCAPTCHA V3 Example

Example: reCAPTCHA V3 verification

How to Solve reCAPTCHA V3​

Step 1: Extract Required Parameters​

You need to find three parameters from the target webpage:

sitekey - Found in:

  • The URI of api.js as the value of render parameter: https://www.google.com/recaptcha/api.js?render=6LfZil0UAAAAAAdm1Dpzsw9q0F11-bmervx9g5fE
  • The grecaptcha.execute() JavaScript call
  • The ___grecaptcha_cfg configuration object

action - Found by inspecting JavaScript code for grecaptcha.execute function:

grecaptcha.execute('6LfZil0UAAAAAAdm1Dpzsw9q0F11-bmervx9g5fE', {action: 'do_something'})

If you can't find it, the default value is "verify".

pageurl - Full URL of the page where you see the reCAPTCHA V3

Step 2: Submit the Task to CaptchaAI​

Send a GET request to https://ocr.captchaai.com/in.php with sitekey, action, and page URL:

import requests

# Submit the captcha task
params = {
    'key': 'YOUR_API_KEY',
    'method': 'userrecaptcha',
    'version': 'v3',
    'googlekey': '6LfZil0UAAAAAAdm1Dpzsw9q0F11-bmervx9g5fE',
    'action': 'login',
    'pageurl': 'https://example.com/page',
    'json': '1'
}

response = requests.get('https://ocr.captchaai.com/in.php', params=params)
result = response.json()
task_id = result['request']
print(f"Task ID: {task_id}")

Step 3: Retrieve the Solution​

Wait 15-20 seconds, then poll for the result using a GET request to https://ocr.captchaai.com/res.php:

import time

time.sleep(15)  # Wait 15 seconds

params = {
    'key': 'YOUR_API_KEY',
    'action': 'get',
    'id': task_id,
    'json': '1'
}

response = requests.get('https://ocr.captchaai.com/res.php', params=params)
result = response.json()

if result['status'] == 1:
    token = result['request']
    print(f"Solution Token: {token}")

Step 4: Submit the Token to Backend​

Important: Unlike V2, you do NOT inject the token into the DOM. Instead, send it in your backend request:

# Send token to the backend
import requests

data = {
    'username': 'user@example.com',
    'password': 'password123',
    'g-recaptcha-response': token,  # Include the token
    'action': 'login'  # Include the action
}

response = requests.post('https://example.com/api/login', data=data)
print(response.text)

Response Format​

JSON Response (with json=1):

{
  "status": 1,
  "request": "03AHJ_Vuve5Asa4koK3KSMyUkCq0vUFCR5Im4CwB7PzO3dCxIo..."
}

Plain Text Response:

OK|03AHJ_Vuve5Asa4koK3KSMyUkCq0vUFCR5Im4CwB7PzO3dCxIo...

Common Errors​

  • ERROR_WRONG_USER_KEY: API key is incorrect format. Check your API key (32 characters).
  • ERROR_KEY_DOES_NOT_EXIST: API key doesn't exist. Verify your API key.
  • ERROR_ZERO_BALANCE: Insufficient account balance. Top up your account to continue.
  • ERROR_PAGEURL: pageurl parameter is missing. Provide the full page URL.
  • ERROR_WRONG_GOOGLEKEY: sitekey is blank or malformed. Verify the sitekey extraction.
  • CAPCHA_NOT_READY: Solution not ready yet. Wait 5 seconds and poll again.

For complete error documentation, see the Error Handling Guide.

Tips & Best Practices​

Tip: Always find the correct action name - it's crucial for matching the expected behavior.

Tip: Use json=1 parameter for structured responses that are easier to parse.

Tip: Send the token immediately after receiving it - tokens expire within minutes.

Tip: Include proxy and user-agent for better accuracy on protected sites.

API Reference​

For complete API specifications and advanced options, visit the CaptchaAI API Documentation and select reCAPTCHA V3 from the sidebar.