Puzzle captcha is a simple front end based alternative for google Recaptcha which will challenge the automated programs with simple puzzles.
Add this HTML tag before the submit button of your form
<div id="puzzle-captcha"></div>HTML code to link the files
<link rel="stylesheet" href="src/puzzlecaptcha.css">
<script type="text/javascript" src="src/puzzlecaptcha.js"></script>Verify before submitting your form using
isPuzzleCaptchaSolved()Some screenshots
This captcha program is not suitable for the website to protect some important forms from highly advanced automation