Akismet is one of the most popular and most effective anti spam plugin for WordPress. However, it is not free for blogs that are making money. Here are some anti spam plugins for WordPress that are completely free, and are good alternatives to Akismet. These WordPress anti spam plugins help reduce both comment spam as well as trackback spam.
Blogging requires efforts and your main focus must be on creating quality content rather than filtering & fighting spam on your own. Just, leave the headache on an anti-spam plugin of your choice and become more productive.
Many of the bloggers claim that Bad Behavior is one of the best anti spam plugins for WordPress. Bad Behavior not only prevents comment spam, it also protects fraudulent users from visiting your website at all. If your website content is requested from a client that Bad Behavior determines to be spammy, it will not serve website content at all. However, if it accidentally prevents legitimate human visitors from seeing your website, it lets them perform a simple action to see your website content. Bad Behavior mentions that it is best used in conjunction with other anti spam plugins. My personal choice would be to pair Bad Behavior with a Captcha plugin.
AntiSpamBee is another sophisticated free antispam plugin for WordPress. AntiSpamBee uses sophisticated techniques, and analyzes comments as well as trackabacks or pings. This ensures that your blog is safe from both comment spam as well as ping spam.
AVH First Defense Against Spam
AVH First Defense against spam is a free anti spam plugin for WordPress that prevents spam by comparing IP address of your visitors with blacklists of IP addresses maintained by StopForumSpam and Project HoneyPot. If IP of your visitor is a know spam IP, the content of your website will not be served to it. One big limitation of this plugin is that it works for only those websites that get less than 5000 unique visitors daily. If your website gets more than 5000 unique visitors daily and you use this plugin, it is possible that your content is not served to even legitimate visitors.
Defensio Anti-Spam is one of the advanced anti spam plugins for WordPress. This keeps learning behavior of your website visitors, and spam detection and accuracy keeps on increasing over time. It also provides support for OpenID, and provides detailed charts and feed of comments. This anti spam plugin discourages to be used with other anti spam plugins.
Spam-Stopper is a captcha plugin for WordPress that asks simple questions to visitors before they can post a comment. An example question is “Is the sky Green”. Many people do not favor such captcha plugins as these plugins tend to discourage legitimate comments as well. However, personally, I am a big fan of such plugins. I run many websites any whenever any website starts getting lot of spam, the first thing I do is to install a captcha plugin and that virtually brings down the spam to zero.
Cookies for Comments
Cookies for Comments antispam plugin uses two approaches to block spam comments. Firstly, it downloads a cookie on the visitor’s PC, and checks for presence of that cookie when comment is posted. In case the cookie was missing, this might mean that the website was opened in some auto-commenting software. Secondly, it checks how much time it takes user to enter comment. If the visitor was able to post comment too quickly, it is probably a spam.
Peter’s Custom Anti-Spam
Peter’s Custom Antispam is another captcha plugin for WordPress that asks users to first enter a word that is displayed in the image. A good feature of this captcha plugin is that it lets you customize the list of words that can be displayed.
CloudFlare is not an antispam plugin, but a service that stops your website content from being served to malicious IPs. It also works as a free CDN option to speed up your website.
Animal Captcha is another captcha plugin for WordPress that prevents comment spam by asking visitors to identify two animals. Two animal images are shown side-by-side, and visitors are asked to identify them before being able to post comments.
Solve Media: Make Money from Captchas
Another interesting captcha option for WordPress is Solve Media. It also adds a captcha below your comment form. However, the way it differs from other captcha plugins is that it pays you everytime someone fills that captcha! The reason I am not using this plugin is because it pays too less, and the minimum payment is quite high. If your visitors leave a lot of comments, then you can make some money with this captcha plugin.