Comment spam is a fact of life if you have a blog, no matter which platform you’re using. On WordPress, you not only have solid built-in tools to prevent comment spam, but there are also a wide range of comment spam protection and defense plugins and methods to choose from if you feel you need additional coverage and protection.

You should know that there is no “one size fits all” method that will protect your comments; spammers are clever and use many different tactics. Consider using multiple plugins. Remember that spammers are constantly changing the way they attack so you must keep your choices updated.

We have compiled a list of some of the Best WordPress AntiSpam Plugins in 2010. We suggest you try them out and see which ones work best for you.

1. Akismet

Akismet is the most popular anti spam plugin for WordPress. It comes installed by default with WordPress. However, in order to use Akismet, you have to register an account at WordPress.com and get an API key. When new comment are posted within one of your posts, Akismet will check the comment through the web service to determine if it is spam. Suspected comments will be marked as spam and admins can review them in the admin interface to double-check.

2. WP-SpamFree

WP Spam Free is an extremely powerful Anti-Spam plug-in that virtually eliminates comment Spam. Finally, you can enjoy a Spam-free WordPress blog! Includes Spam-free contact form feature as well. Some people prefer this over Akismet. You should try them both.

3. SI Captcha

One of the best Captcha Plugins on the web! Adds CAPTCHA anti-spam fields to WordPress on the comment form, registration form, login, or all. In order to post comments or register, users will have to type in the code shown on the image. This prevents spam from automated bots. Adds security. Works great with Akismet. Also is fully WP, WPMU, and BuddyPress compatible.

4. WP-Hashcash

WP Hashcash is an antispam plugin that is said to completely eradicate comment spam on WordPress blogs. It does so by making your visitors submit a proof-of-work that indicates they opened your website in a web browser, not a robot. If the validation fails, WP Hashcash gives you 3 options: putting the comment into moderation (default), put the comment in the akismet queue, or delete it.

5. Math Comment Spam Protection

This simple plugin will display the commentators a simple math question that they need to solve before they can post their comments. It doesn’t require Javascript or cookies to work which should make it work in any environment and on any browser.

6. bcSpamBlock

This is a light WordPress plugin to fight spam. Users with Javascript enabled will not see any difference while users with Javascript disabled will need to copy and paste a small string into a textbox. Basically the plugin will generate a random ID and then encrypt it. When the comment form is submitted, the plugin will re-encrypt the random ID and compare to make sure it matches the crypt value.

7. DNS-anti-spam

This plugin works two ways. First, it will check the comentator’s IP to determine whether it is part of the known blacklisted IPs, and then checks the content of the comment against a huge list of known spammer websites.

8. WP-SpamFree

Again, this is a very powerful antispam plugin for WordPress that helps you eliminate comment spam, including trackback and pingback spam. There is an interesting feature called Enhanced Comment Blocklist, which is able to block the comment if it contains blacklisted keywords.

9. Bad Behavior

Bad Behavior is designed to act as a gatekeeper and it is able to prevent spammers even from entering your blog. This Plugin analyzes the delivery method as well as the software being used by the Spammer.

10. Email Protect

This is a very useful plugin to protect your email addresses from automatic Email Extractors and Grabbers. Email Protect will automatically change any email addresses in your blog to an image to prevent spam bots from harvesting them.

Amine Rahal

Passionate about the world wide web since 1995, Amine has been working as a Web Developer, SEO & Social Media Marketing Specialist for several Organizations in the United States, Canada and China.