gh0stpr3ss

No more need for captchas, making your readers jump through hoops in order to comment. Instead, activate this plugin and let a simple hidden honeypot input field catch spam bots, which will fill out all fields in the form (even our hidden honeypot field). If that honeypot field isn’t empty, the comment won’t process, effectively nuking most spam comments.
I also made sure that the id of the field is utilizing a random string of letters and numbers every time the page is loaded (ie: 34rscsDW37g8gf) so that spam bots can’t target a specific id name in order to bypass it, making it harder for the bots to win.
Installation is dead simple, just activate the plugin and you’re done. No other steps required on your end, the plugin handles everything.
<h3>Additional info</h3>
The basic structure of this plugin was cloned from the <a href="https://github.com/tommcfarlin/WordPress-Plugin-Boilerplate" rel="nofollow ugc">WordPress-Plugin-Boilerplate</a> project.
This plugin supports the <a href="https://github.com/afragen/github-updater" rel="nofollow ugc">GitHub Updater</a> plugin, so if you install that, this plugin becomes automatically updateable direct from GitHub. Any submission to WP.org repo will make this redundant.

Honeypot Comments

Plugin to stop most comment spam by adding in a simple honeypot for spam bots to get caught in.

Automattic

Donncha O Caoimh (a11n)

This plugin adds a stylesheet or image to your blog’s html source code. When a browser loads that stylesheet or image a cookie is dropped. If that user then leaves a comment the cookie is checked. If it doesn’t exist the comment is marked as spam. 
The plugin can also check how long it took a user to enter a comment. If it’s too fast it’s probably a spam bot. How fast can a legitimate user enter their name, email, web address and enter a well thought out comment?
For the adventurous, add these lines to your .htaccess and it will block spam attempts before they ever get to WordPress. Replace the Xs with the cookie that was set in your browser after viewing your blog. You can also find the cookie value by examining the page source code and looking for “css.php?k=XXXXXXXXXXXXXXXXXXX”. Make sure the lines go above the standard WordPress rules.
<pre><code> RewriteCond %{HTTP_COOKIE} !^.*XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.*$
 RewriteRule ^wp-comments-post.php - [F,L]
</code></pre>
If you use WordPress MU, replace wp-comments-post.php above with wp-signup.php to block spam signups.
<pre><code> RewriteCond %{HTTP_COOKIE} !^.*XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX.*$
 RewriteRule ^wp-signup.php - [F,L]
</code></pre>

Cookies for Comments

If you don't use any other spam filter plugins, then you can rely on this to stop spam comments for sure!

Must have, if you don't use any other spam filters!

I'd been getting a dozen spams a day on two of my sites. We installed "Stop Spam Comments" on one and "Cookies for Comments" on the other. Both worked perfectly. No more spam. Thanks!



very easy and no more spam!

Sets a cookie on a random URL that is then checked when a comment is posted. If the cookie is missing the comment is marked as spam.

Honeypot Comments vs Cookies for Comments