# 动态 CAPTCHA 解决

默认情况下，无头浏览器会在页面加载时自动检测并立即解决 CAPTCHA。不过，有些网站会在后续阶段显示 CAPTCHA，例如在提交表单时或在特定用户交互后弹出的窗口中。

无头浏览器允许您在会话中的任何时刻手动触发 CAPTCHA 检测和解决。要手动触发 CAPTCHA 解决，请执行以下代码，向 window 对象发送消息：

```
window.postMessage({action: 'solve_captcha', type: '<captcha type>'}, '*')
```

支持的 CAPTCHA 类型包括：

* `hcaptcha`
* `recaptcha`
* `turnstile` （Cloudflare CAPTCHA）

使用示例（Playwright / Puppeteer JavaScript）：

```
// ...
await page.click('#form-submit');
// 现在我们知道应该显示 CAPTCHA 了
await page.evaluate(() => {
  window.postMessage({action: 'solve_captcha', type: 'recaptcha'}, '*')
});
// 像常规情况一样关注 `oxylabs-captcha-start` 和 `oxylabs-captcha-end` 事件
// ...
```

`Turnstile` CAPTCHA 需要采用不同的方法，因为必须在它出现在屏幕上之前进行拦截。为此，请先启动 CAPTCHA 检测，然后执行会触发 CAPTCHA 的操作：

```
// 我们知道下一步操作可能会触发 Turnstile CAPTCHA
await page.evaluate(() => {
  window.postMessage({action: 'solve_captcha', type: 'turnstile'}, '*')
});
await page.click('#form-submit');
// 像常规情况一样关注 `oxylabs-captcha-start` 和 `oxylabs-captcha-end` 事件
// ...
```


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