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How to identify and find the values of reCAPTCHA V3

How to identify and find the values of reCAPTCHA V3

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28-Aug-2023

Solver reCaptcha v3

What does "score" signify in V3 and why is there no captcha?

reCAPTCHA V3 is not your regular captcha task. It's not an automated Turing test to distinguish robots from humans. reCAPTCHA V3 is a browser scoring mechanism that recognizes who operates the browser, a human or a program. The result of solveing reCAPTCHA V3 is a score from 0.1 to 0.9 where 0.1 is "most likely a robot" and 0.9 is "most likely a human". Capsolver provides tokens with a 0.9 score.

How do I know there is a reCAPTCHA V3?

  • reCAPTCHA V2: There is a checkbox on a page.
  • reCAPTCHA V2 Invisible: There is no checkbox, but there is a reCAPTCHA logo in the bottom right corner. Sometimes you are asked to solve a reCAPTCHA if they detect that you are a suspicious user.
  • reCAPTCHA V3: There is no checkbox, but there is a reCAPTCHA logo in the bottom right corner. You are never asked to solve a reCAPTCHA.

Sometimes it is really tricky to distinguish between a reCAPTCHA V2 Invisible and a V3. In such cases, simply open the browser's console Command+Option+C (Mac) or Control+Shift+C (Windows, Linux, Chrome OS) and check the requests sent to google.com (or recaptcha.net in some cases) on a Network tab.

Find a request
https://www.google.com/recaptcha/api2/reload?k= for reCaptcha v3 or https://www.google.com/recaptcha/enterprise/reload?k= for reCaptcha v3 Enterprise

Then check for
https://www.google.com/recaptcha/api2/userverify?k=

The first request should always be there. If you cannot find it, try to change the hostname to "recaptcha.net" and look for it until you find it. If you cannot find the second request to userverify, then it's a case of reCAPTCHA V3. If there is a request to userverify, then it's a reCAPTCHA V2 Invisible.

How to find "googlekey" and "action"

There are some ways to find google key and the action paramters, some are more effective than others. First option is the best way to find these values.

Method #1:

Read this https://www.capsolver.com/blog/Extension/identify-any-captcha-and-parameters

Method #2:

  1. Download Charles Proxy

  2. Right click to the request that we can see with the name https://google.com

  3. Click enable ssl

    After it's clicked, should look like this:

  4. To identify the google key and also the action parameter, we just need to go to the site and trigger the reCaptcha v3 with Charles Open

    In this case, it's reCaptcha v3 Enterprise, but a request should appear there. The red line is the google key

  5. Now that you have the google key, it's time to find the action. Click the reload request and in the right menu, click ProtoBuf

  6. After click, some values will appear, we need to find a parameter that is text and looks like a action parameter, in this case:

    LOGIN_USER_SEARCH is the action parameter.

Method #3:

  • googlekey: Open a webpage with captcha and go to the browser's console.
    Find an iframe with a captcha challenge. You may search for src="https://www.google.com/recaptcha/api2/anchor
    Now find the k parameter in the script address. That's the googlekey you are looking for. It is static for every particular website that uses Google reCAPTCHA.
  • action: Open a webpage with captcha and go to the browser's console. Now find a script calling the *grecaptcha.execute method. Arguments used to call this method may contain an action parameter. If it's there, pass it in your request to in.php when you upload your task. If there is no action, you don't need to send it.

How google reCaptcha v3 scores work?

There are 11 levels of reCAPTCHA, with scores ranging from 0.0 to 1.0. A score of 1.0 means the interaction is low risk and almost certainly real, while a value of 0.0 means the connection is high risk and perhaps fake.

How to solve reCaptcha v3

Step 1: Submitting the information to capsolver

POST https://api.capsolver.com/createTask
{
  "clientKey":"yourapiKey",
    "task":
        {
          "type":"ReCaptchaV3Task",
        "websiteURL":"https://antcpt.com/score_detector",
        "websiteKey":"6LcR_okUAAAAAPYrPe-HK_0RULO1aZM15ENyM-Mf",
        "pageAction": "homepage",
        "proxy":"yourproxy"
        }
}

Step 4: Getting the results

We will need to retrieve the getTaskResult method until the captcha is solved.

Example:

POST https://api.capsolver.com/getTaskResult
Host: api.capsolver.com
Content-Type: application/json

{
    "clientKey":"YOUR_API_KEY",
    "taskId": "TASKID OF CREATETASK" //ID created by the createTask method
}

After the captcha has been solved, you can check the captcha token by sending the token to the site.

For more information of how to solve reCaptcha v3, please check this blog: Solve reCaptcha v3 with human score

Capsolver Team 💜

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