What is Captcha?
The full form of captcha is Completely Automated Public Turing test to tell Computers and Humans Apart. This is basically a challenge to differentiate human and a computer software. A CAPTCHA is only solved by human being.
WordPress captcha plugin helps to stop spam attack and unwanted users from your WordPress website. The captcha plugins allow you to implement a super security captcha into your website forms like login form, registration form, password recovery form, comment form and any other form which you are using for website and protect against spam.
5 Best Free Captcha Plugins
SI CAPTCHA Anti-Spam – This is one of the best plugin for anti spamming. This plugin adds captcha to WordPress forms for comments, registration, lost password, log in or all. In order to post comments or register, users will have to type in the code shown on the image. This adds security and prevents spam from automated bots. This plugin also compatible with WPMU, and BuddyPress compatible.
WP-reCAPTCHA – reCAPTCHA is also a best and most popular plugin. This plugin protects your site against spam, malicious registrations and other forms of attacks where computers try to disguise themselves as a human. reCAPTCHA comes in the form of a widget that you can easily add to your blog, forum, registration form, etc.
WP Captcha Bank –This is a powerful WordPress shield which allows you to protect your WordPress website from SPAM. You can display Captcha on Login Form, Registration Form, Comment Form, Admin Comment form, Contact Bank Form and Hide Captcha for registered users easily.Captcha Bank is loaded with more than 50+ settings including advance protection features such as Login Logs, Auto IP Block, Security Protections and much more.
Captcha – The Captcha plugin allows you to implement a super security captcha form into web forms. It protects your website from spam by means of math logic. You will not have to spend your precious time on annoying attempts to understand hard-to-read words, combinations of letters or pictures that make your eyes pop up. All you need is to do one of the three basic maths actions – add, subtract and multiply.