# Find reCAPTCHA parameters

> How to find reCAPTCHA's websiteKey (sitekey), websiteURL, the v3 pageAction and the callback function in the browser's Network, Sources and Console panels, with a script that finds them automatically.

Source: https://docs.yescaptcha.com/en/guides/find-recaptcha-parameters/ · Last verified: 2026-10-15

A reCAPTCHA task needs `websiteURL` (the page showing the captcha) and `websiteKey` (the site key); v3 also needs `pageAction`. When you drive a browser with Selenium or similar, you also need the callback function. All of these can be found with the browser’s developer tools (F12).

## The fastest way: a lookup script

Open the page with the captcha, open the Console (F12), paste this and run it:

find-recaptcha-clients.js

```js
// Paste into the browser DevTools console on a page with reCAPTCHA, then run findRecaptchaClients().
// Lists every reCAPTCHA on the page: version (V2/V3), sitekey, page URL and the callback function.
function findRecaptchaClients() {
  if (typeof ___grecaptcha_cfg === 'undefined') return [];
  return Object.entries(___grecaptcha_cfg.clients).map(([cid, client]) => {
    const data = { id: cid, version: cid >= 10000 ? 'V3' : 'V2' };
    const objects = Object.entries(client).filter(([, value]) => value && typeof value === 'object');
    objects.forEach(([toplevelKey, toplevel]) => {
      const found = Object.entries(toplevel).find(
        ([, value]) => value && typeof value === 'object' && 'sitekey' in value && 'size' in value,
      );
      if (toplevel instanceof HTMLElement && toplevel.tagName === 'DIV') data.pageurl = toplevel.baseURI;
      if (found) {
        const [sublevelKey, sublevel] = found;
        data.sitekey = sublevel.sitekey;
        const callbackKey = data.version === 'V2' ? 'callback' : 'promise-callback';
        const callback = sublevel[callbackKey];
        if (!callback) {
          data.callback = null;
          data.function = null;
        } else {
          data.function = callback;
          const keys = [cid, toplevelKey, sublevelKey, callbackKey].map((key) => `['${key}']`).join('');
          data.callback = `___grecaptcha_cfg.clients${keys}`;
        }
      }
    });
    return data;
  });
}

findRecaptchaClients();
```

In the output, `sitekey` is the `websiteKey`, `pageurl` is the `websiteURL`, `version` tells v2 from v3, and `function` and `callback` are the callback:

```json
[
  {
    "id": "0",
    "version": "V2",
    "sitekey": "6Le-wvkSAAAAAPBMRTvw0Q4Muexq9bi0DJwx_mJ-",
    "function": "onSuccess",
    "callback": "___grecaptcha_cfg.clients['0']['l']['l']['callback']",
    "pageurl": "https://www.google.com/recaptcha/api2/demo"
  }
]
```

An empty array means reCAPTCHA hasn’t loaded yet; run it again once the captcha appears.

## websiteKey and websiteURL

In the Network panel, search for `anchor` and find a request like:

```text
https://www.google.com/recaptcha/api2/anchor?ar=1&k=6LfW6wATAAAAAHLqO2pb8bDBahxlMxNdo9g947u9&co=...&hl=en&size=normal
```

-   The value after `k=` is the `websiteKey`.
-   `websiteURL` is the full URL of the page showing the captcha (usually this request’s `Referer`).

You can also search the page source for `data-sitekey`.

## pageAction (v3)

`pageAction` is the `action` the page passes in `grecaptcha.execute(SITE_KEY, {action: '...'})`, and it must match.

**Method 1: search the source.** In the Sources panel, right-click and choose “Search in all files”. Search `.execute(` for v3, or `.enterprise.execute` for v3 Enterprise, and look at the `action` that follows:

```js
grecaptcha.ready(function () {
  grecaptcha.execute('6LdpS-gUAAAAAL3Qr2yP7rkrQjkKBVvEY_48JS5l', { action: 'login' }).then(function (token) {
    // ...
  });
});
```

Here `pageAction` is `login`.

**Method 2: a breakpoint.** If the code is obfuscated and search finds nothing, run `debug(grecaptcha.execute)` in the console (`debug(grecaptcha.enterprise.execute)` for Enterprise), then do whatever triggers verification on the page (for example click “Log in”). When the debugger stops, read `action` in the Scope panel.

A site may use different actions at different steps (for example `signup/submit_email` and then `signup/success`); use the one for the step you need to pass. Press F8 to continue to the next call.

## Callback function

When you put a token into a page with Selenium or similar, you then call the page’s callback to tell it verification is complete:

-   Search the Elements panel for `data-callback`; its value is the function name, for example `data-callback="onSuccess"`.
-   Or search for `grecaptcha.render` and read the `callback` option.
-   Or inspect `___grecaptcha_cfg.clients` in the console, or use the lookup script above.

Calling it:

```python
driver.execute_script("onSuccess(arguments[0])", g_recaptcha_response)
```

Some pages have no callback; put the token into the `g-recaptcha-response` textarea and submit the form. The full flow: [Submit a reCAPTCHA token](https://docs.yescaptcha.com/en/guides/submit-recaptcha-token/).