Akismet checks your comments against the Akismet Web service to see if they look like spam or not.
Adds CAPTCHA anti-spam methods to WordPress on the forms for comments, registration, lost password, login, or all.
No spam in comments. No captcha.
All-in-one WordPress spam protection, with NO CAPTCHAs, challenge questions or other inconvenience to site visitors.
A lightweight plugin to protect email addresses from email-harvesting robots by encoding them into decimal and hexadecimal entities.
Todd Lahman's comment spam blocking plugin that blocks automated spam with zero false positives.
Defeat automated spambots (even the new 'learning' bots with dynamically named hidden fields) by adding a client side generated checkbox.
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.
The most advanced protection against sploggers and spam users registration, is fully WordPress,WordPress MU ,BuddyPress and bbPress 2.0 compatible
To protect your Blog from automated spambots, this plugin adds invisible formfields to your comment form.
Dead simple and super lightweight anti-spambot WordPress plugin. No captcha, tricky questions or any other user interaction required at all.
Smart invisible captcha for wordpress comments
The AVH First Defense Against Spam plugin gives you the ability to block spammers before any content is served.
Asks commenters to complete a simple CAPTCHA if they don't have a previously approved comment, or if Akismet thinks their comment is spam.
This plugin prevents users from commenting or viewing your website if a comment of theirs has been marked as spam.
Anti-Captcha is a transparent spam solution that does not require any end-user interaction.
A clean, secure, plug-&-play contact form for WordPress.
Asks the visitor making the comment to answer a simple math question. This is intended to prove that the visitor is a human being and not a spam robot
An extremely powerful antispam plugin that blocks spam-bots without annoying captcha images.
Sabre is an acronym for Simple Anti Bot Registration Engine. It's a set of counter measures against spam registration on your blog.
Performs a simple but very effective test on all incoming trackbacks in order to stop trackback spam.
Several types of captcha to protect your site in one easy to use plugin.
WP Anti Spam can anti automated spambots or anti spams by"comment","ip","name","email","url".
REPLACEMENT of the original Simple Trackback Validation Plugin from Miachel. Performs a simple but very effective test on all incoming trackbacks in o
Kills spam dead in it's tracks. Be gone evil demon spam!
Simple IP Ban is a lightweight ip / user agent ban plugin.