icon Captcha

The Captcha control blocks spammers and bots and authenticates that a real person submits a form. If you publish your form on a public site, we recommend adding the Captcha control.

Captcha control preview

This page contains a detailed description of the control properties and JavaScript samples, which you can use with this control.


Here you can find properties related to the Captcha control.


A unique identifier for the control.

Name property

Site Key

The Captcha control is based on Google’s ReCAPTCHA. To start using the Captcha control, you need to create a key pair for the sites where you plan to add a form.

Site Key property

To create a site key:

  1. Login to the ReCAPTCHA admin page using your Google account.

  1. Give a name to the connection:


  1. Select reCAPTCHA v2 type:


  1. Add all domains where you plan to use a form:


  1. Accept the terms of service and click Submit. You will be redirected to the page with the Site Key. Copy the site key and paste it to the Site Key property:

    Copy Site Key


The property defines the size of the control.

Size property

You can choose between Normal and Compact sizes.

Normal size:

Normal size

Compact size:

Compact size


The property defines the control theme.

Theme property

You can choose between Light and Dark themes.

Light theme:

Light theme

Dark theme:

Dark theme