Bleep Filter

The Bleep Filter plugin is a free and open source advanced content filtering plugin for WordPress. Commonly used as a bad word filter and swear filter, this plugin offers a variety of applications for your needs. Easily add the words you want to filter out and the plugin will find those words in your blog’s comments, posts, and rss feeds and passively replace them in a variety of styles.

Using a highly advanced phonetic algorithm, not only is the spelling being detected but also how the word sounds. This makes it much more difficult for mischievous posters to bypass the filter intentionally.

With the Bleep Filter plugin all you have to do is add your words and the plugin takes care of the rest.