# Captcha

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

![](https://1025048312-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-M8fLhS0bmfBRyq0HdUm%2F-MBy4b-tXZfmMOm9MbWX%2F-MBy5QAqrgGz83CriyXa%2Fimage.png?alt=media\&token=0077d91e-3cbd-4654-9ed2-42a910a6dd8d)

## 🔅 Captcha properties

You may configure additional captcha properties from the [answer properties](https://docs.ngsurvey.com/form-management/form-designer/answers/answer-properties) 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](https://docs.ngsurvey.com/installation-setup/system-settings/google/captcha). 
* **`Google's recaptcha secret key`** your personal [secret key](https://docs.ngsurvey.com/installation-setup/system-settings/google/captcha) 
* **`Google recaptcha URL`** [verification URL](https://docs.ngsurvey.com/installation-setup/system-settings/google) 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](https://docs.ngsurvey.com/installation-setup/system-settings/google) or from the [answer properties](https://docs.ngsurvey.com/form-management/form-designer/answers/answer-properties).
{% endhint %}