There is a basic Captcha system available for the contact form in Cleanstart HTML.
It is PHP-based and does not use the Google reCaptcha system.

In order to enable the Captcha system included with our theme, please follow the steps below:

1) Edit the contact_form.js file and change the following line:

var enableCaptcha = false;

 

To:

var enableCaptcha = true;

 

2) Edit the contact.php file and change the following line:

$enableCaptcha = false;

 

To:

$enableCaptcha = true;

 

3) Edit the contact.html file and add the following snippet anywhere you want the captcha to be displayed on the form:

<!-- CAPTCHA -->
<span><img src="./captcha/captcha.php"></span>
<input type="text" id="captcha" />
<!-- /CAPTCHA -->

 

For example you can add it after the submit area:

<div class="col-sm-12 col-md-12"><br/>

<a id="submit_btn" class="btn btn-primary" name="submit">Submit Message</a> <span id="notice" class="alert alert-warning alert-dismissable hidden" style="margin-left:20px;"></span>

<!-- CAPTCHA -->
<span><img src="./captcha/captcha.php"></span>
<input type="text" id="captcha" />
<!-- /CAPTCHA -->

</div>

 

Thank you for using Cleanstart HTML!