Kills spam dead in it's tracks. Be gone evil demon spam!
Simple IP Ban is a lightweight ip / user agent ban plugin.
Captcha Bank is an easy to use wordpress security plugin to prevent spam on your site while letting real people pass through with ease. It's more
Provides Visually Appealing Captchas to Enhance and Secure your WordPress pages. Fortified with ANTI-SPAM FILTER Protection and SPAM COUNTER.
Adds the new google “Are you robot?” recaptcha to wp-login page, registration page, comment forms, buddypress registration page and contact form 7
Blue Captcha is a powerful and highly customized WordPress plugin that effectively protects your WP blogs from spammers and unwanted persons.
Combat spam registrations for a BuddyPress-powered site using Google's reCAPTCHA
Comment spam prevention without moderation, captchas or questions
Spam Master is the Ultimate Spam Protection plugin that blocks new user registrations and post comments with Real Time anti-spam lists.
This plugin adds a reCAPTCHA form to BuddyPress registration form to keep your community spam free.
Kills spam-bots, leaves humans standing. No CAPTCHAS, no math questions, no passwords, just spam blocking that stops spam-bots dead in their tracks.
Centrora Security plugin is excellent for security management. It incorporates firewall, dedicated malware scanners to enhance WordPress security.
An easy to use wordpress Captcha plugin to prevent spam on your site. You can use Image Captcha to protect comments and the admin panel.
Reduces spam and troll comments by requiring commenters to answer a question.
Plugin to reject spam. Port from same author from http://www.phpbbantispam.com Actually visits the URL from commenter to spider for spamwords.
yaCAPTCHA is a CAPTCHA plugin for WordPress that helps you block comment spam from automated bots.
Stop a lot of spambots from polluting your site by making visitors identify a custom word displayed as an image before commenting.
MP Spam Be Gone is the simplest, most effective Spam blocker.
Blocks referer/referral spam from accessing your site and cleans up your Google Analytics in the process!
Adds custom user fields to better manage users & members & customize login-registration page css & messages. Lets you customize the entire
This antispam plugin provides very simple(one-click) and powerful captcha for your blog.
Create responsive contact forms, order forms, registration forms and more. For free and without ever leaving WordPress.
This plugin allows WordPress to block over 95% of spam comments using a time-based hash.
This plugin removes all HTML tags, BBCode tags and links from added comments (including link to author's website)
Block 250+ spam sites, such as semalt.com and 4webmasters.org! Keep your website safe and your Google Analytics statistics clean and accurate.
This plugin is discontinued now. Sorry!