# captcha prop

The `captcha` property can be used to change the appearance of the CAPTCHA widget.

## Properties

| Name                                                        | Type                                                                                                                                                                                                                                | Description                                  |
| ----------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------- |
| theme                                                       | 'auto' | 'light' | 'dark'                                                                                                                                                                                                         | The CAPTCHA widget theme. Defaults to auto.  |
| size                                                        | 'normal' | 'flexible' | 'compact'                                                                                                                                                                                                 | The CAPTCHA widget size. Defaults to normal. |
| appearance.captcha.language: Set by this language property. | localization.locale: Set by the localization prop on <ClerkProvider>. Some languages are supported by Clerk but not by Cloudflare Turnstile, which is used for the CAPTCHA widget. See Cloudflare Turnstile's supported languages. |                                              |

## Usage

To customize the CAPTCHA widget, pass the `appearance` prop to the [clerk()](https://clerk.com/docs/astro/reference/astro/overview.md) integration. The `appearance` prop accepts the property `captcha`, which can be used to apply different changes to the widget.

In the following example, the CAPTCHA is customized to use the dark theme, a flexible size, and Spanish as the display language.

filename: astro.config.mjs
```js
import clerk from '@clerk/astro'

export default defineConfig({
  integrations: [
    clerk({
      appearance: {
        captcha: {
          theme: 'dark',
          size: 'flexible',
          language: 'es-ES',
        },
      },
    }),
  ],
})
```

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