Akismet checks your comments against the Akismet Web service to see if they look like spam or not.
#1 super security anti-spam captcha plugin for WordPress forms.
No spam in comments. No captcha.
All-in-one WordPress spam protection, with NO CAPTCHAs, challenge questions or other inconvenience to site visitors.
Contact Form 7 Honeypot - Adds honeypot anti-spam functionality to CF7 forms.
Protect WordPress website forms from spam entries with Google reCaptcha.
Todd Lahman's comment spam blocking plugin that blocks automated spam with zero false positives.
Bad Behavior prevents spammers from ever delivering their junk, and in many cases, from ever reading your site in the first place.
Spam protection, anti-spam, all-in-one, premium plug-in. No comments spam & users spam, no contact form & WooCommerce spam. Forget spam.
Powerful anti-spam plugin that eliminates blog comment spam. Finally, you can enjoy a spam-free WordPress blog! Includes contact form.
Aggressive anti-spam plugin that eliminates comment spam, trackback spam, contact form spam and registration spam. Protects against malicious attacks.
This plugin utilizes Google reCAPTCHA to help your blog stay clear of spams. BWP reCAPTCHA supports no CAPTCHA reCAPTCHA, Contact Form 7 and Akismet.
Gwolle Guestbook is the WordPress guestbook you've just been looking for. Beautiful and easy.
Encode mailto links, email addresses, phone numbers and any text to hide them from (spam)bots. Mailto links will be protected automatically.
Math Captcha is a 100% effective CAPTCHA for WordPress that integrates into login, registration, comments, Contact Form 7 and bbPress.
Protection against brute force attacks and bots. Restrict login by IP access lists. Monitor user and bot activity. Limit login attempts. reCAPTCHA.
Zero Spam makes blocking spam comments a cinch. Install, activate and enjoy a spam-free site. Even supports third-party plugins!
To protect your Blog from automated spambots, this plugin adds invisible formfields to your comment form.
An extremely powerful antispam plugin that blocks spam-bots without annoying captcha images.
Protect email addresses and mailto links from spambots and spamming. Easy to use without configuration.
The plugin adds a No CAPTCHA reCAPTCHA tag in Contact Form 7, which can be used to include a No CAPTCHA reCAPTCHA anti-spam field.
Contact form with captcha plugin allows you to use a Google reCAPTCHA contact form on your blog. It requires PHP 5.0 or later.
A clean, secure, plug-&-play contact form for WordPress.
Sabre is an acronym for Simple Anti Bot Registration Engine. It's a set of counter measures against spam registration on your blog.
Kills spam dead in it's tracks. Be gone evil demon spam!
Several types of captcha to protect your site in one easy to use plugin.
Comment spam prevention without moderation, captchas or questions
Protect your site against bad bots by trapping them in a virtual blackhole.
Blue Captcha is a powerful and highly customized WordPress plugin that effectively protects your WP blogs from spammers and unwanted persons.