CAPTCHA is designed to recognize the difference between a bot and human and sometimes even malicious software to provide the security to your web system. You have seen Captcha at the time of signup, putting comments on any site, contact forms etc. Here are 10 jQuery Captcha plugin that helps you protect your web pages from bots and spammers.
QapTcha is a draggable jQuery captcha system with jQuery UI ! QapTcha is an easy-to-use, simple and intuitive captcha system. It needs human action instead of to read a hard text and it is a very lightweight jQuery plugin.
This plugin is designed to help overcome automated form submission by requiring a “real person” to identify text made up of dots. The entered value is compared on the server with the generated value to determine whether processing should continue.