One of the unfortunate realities of hosting a WordPress blog is that sooner or later (and probably sooner) you are going to be subject to comment spam — those annoying and often nonsensical blurbs posted as comments to your blog posts. The vast majority of this comment spam comes from automated bots that scour the internet tossing their obnoxious little ads and links all over your site. A good portion of it actually comes from people who are paid to deliver these meaningless comments throughout the web. Here are some WordPress plugins to stop comment spam.
It is free if your blog is mall enough. Akismet is a heuristic anti comment spam filter for WordPress blogs. It works by comparing the comment that a user entered to known spam comments. It learns over time, which comments are real and which are spam, and automatically puts the spam comments into your queue for moderation. Akismet gets some fantastic reviews from users and does a shockingly good job at capturing spam into the moderation queue. However, it has some downsides.
Defensio is an advanced spam filtering web service that learns and adapts to your behaviors and those of your readers. Advanced features such as detailed statistics, charts, RSS feed of our comments (innocent and spam) and counter widget are also available. Defensio aims to be an all-in-one anti-spam solution. Therefore, using it along with other anti-spam plugins WILL cause problems. PLEASE deactivate Akismet and other similar plugins before activating Defensio.
Stop a lot of spambots from polluting your site by making visitors identify a random word displayed as an image before commenting. You can customize the pool of words to display.
This plugin allows the banning of domains and email addresses. To install unzip it, drop the file into the plugin directory, and activate it from the plugin menu. After installation you will find a new panel added to in the “Options” administration section called “Registration Blacklist”. Selecting this will show a text box. Simply add domains or full email addresses that host email accounts that you don’t want to be used to register a user account.
This plugin shows a distorted text image the user has to identify to allow his/her comment to be accepted.
Challenge restricts comment spam by throwing the commenter a challenge. The default challenge is an addition and multiplication math question. The challenge and the answer can also be user-defined. They can be of anything including PHP-evaluatable expressions. The positions of the challenge and the answer are also customizable via the plugin’s own ‘Options’ page in the WordPress Admin page. This plugin can also be used to ensure the commenter’s basic intelligence before he/she/it leaves a comment.
The whole idea to this plugin is to keep spammer robots from posting on your blog, reducing the space taken by spam messages in the database, and reducing the stress of being a spam magnet. This plugin adds a field to the comment form which much be answered in order to post.
Spam Karma 2 (SK2) is an anti-spam plugin for the WordPress blogging platform. It is meant to stop all forms of automated Blog spam effortlessly, while remaining as unobtrusive as possible to regular commenters. Spam Karma 2 is the proud successor to Spam Karma, with whom it shares most of the development ideas, but absolutely none of the code.