# Captcha

The captcha answer type will protect your survey against unwanted automated answers from bots. 

![](/files/-MBy5QAqrgGz83CriyXa)

## 🔅 Captcha properties

You may configure additional captcha properties from the [answer properties](/form-management/form-designer/answers/answer-properties.md) page.

* **`Size`** set the size of the captcha from normal to invisible.
* **`Theme`** color theme used to render the captcha.
* **`Google's recaptcha site key`** your personal [site key](/installation-setup/system-settings/google/captcha.md). 
* **`Google's recaptcha secret key`** your personal [secret key](/installation-setup/system-settings/google/captcha.md) 
* **`Google recaptcha URL`** [verification URL](/installation-setup/system-settings/google.md) of the captcha 
* **`Expires after`** minutes after which  the authorization of the captcha is not valid anymore and requires the respondent to re-confirm. 

{% hint style="warning" %}
It requires to have setup the Google captcha settings in your ngSurvey [settings](/installation-setup/system-settings/google.md) or from the [answer properties](/form-management/form-designer/answers/answer-properties.md).
{% endhint %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.ngsurvey.com/form-management/form-designer/answers/answer-types/captcha.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.