Stop a lot of spambots from polluting your site by making visitors identify a custom word displayed as an image before commenting.
Stop a lot of spambots from polluting your site by making visitors identify a random word displayed as an image before commenting and optionally before registering. You can customize the pool of words to display.
Toggle whether registered users need to enter the word
Random font display
No cookies required
Auto-generated audio for visually impaired users
No mapping of words from the code -- words are used once or removed after 24 hours
Reminder of what was entered if you get the word wrong
Selective blocking of trackbacks, pingbacks
Easy to translate
Compatible with caching plugins
Purposely no obscuring techniques so that the anti-spam word is easy to read
The more people who use this plugin, the more motivation for spambots to target it
GD Library and FreeType Library (There's a diagnostic page to tell you whether you have them installed. If needed, just ask your web host to install them!)
WordPress 3.2 or higher