Spam is the bane of blogs, ugly links trying to nest its way into your blog comments section to trick your readers to buy their products, download spyware, or just build links. We don’t want it, none of us do, and luckily there are ways to stop it.

Solutions in the Blog Platform

You can do it manually, which will work perfectly fine to start with. Just moderate every comment, no problem right? Wrong. That will take time, and the more readers and Google juice your blog gets, the more spam will hit you. It is just not humanly possible to manage spam on a larger blog, it will get out of hand really quick.

Enter the anti-spam measures taken by the blogging platforms. In WordPress you can set up a blacklist and stop all comments with more than two links, for instance, which will help out a bit. Similar solutions are available for Movable Type. Problem is, spammers are sometimes very bright, which means that they alter their spam comments to trick you, so you’ll end up with a bunch of spam comments getting by your line of defence.

Enter the Spam Fighting Plugins

The real way to tackle blog spam is using plugins.

Akismet is something of an industry leader, developed by Automattic and shipped with WordPress. The plugin is free for personal use, but there are problogger licenses. Akismet started as a WordPress plugin, but nowadays it is available for other platforms as well, including Movable Type, various forum software, and more.

Defensio is a fairly new anti-spam solution similar to Akismet. It is available for both WordPress and Movable Type, as well as other platforms, which is a good thing. The plugin is free for personal use, but commercial adopters will have to pay.

TypePad AntiSpam is Six Apart’s brand new anti-spam plugin built on the TypePad platform’s spam protection. It’s in beta and totally free at the moment, and available for both Movable Type and WordPress, with more platforms coming soon. The plugin got a very good testimonial from TechCrunch’s Michael Arrington, who puts it in the same level of effectiveness as Akismet, which is a great start. TypePad AntiSpam is a plugin that learns from what you mark as spam, which means that you need to work a bit to get the plugin to be really effective. It will be very interesting to follow this one.

Other options are of course available, mostly for WordPress. Spam Karma 2 used to be a lifesaver for me, until Akismet got really effective, and I’ve had clients being happy with Bad Behaviour. I’d also like to flag for Mollom, an anti-spam plugin for Drupal that is available for WordPress and apparently is looking go the same way as Akismet and TypePad AntiSpam, with wider platform support.

My Weapons of Choice in the Spam War

I used to have a combination of Akismet and Spam Karma 2 on my WordPress blogs, which means most of my sites, and it’s been working really well. However, the last 6 months or so I’ve settled for Akismet, and actually haven’t had the need to utilize any other anti-spam plugin. Defensio is yet to impress me, although I wouldn’t rule it out. I am waiting for more users to report on how it is working for them, should it get a lot of positive press I’ll probably give it a serious go on one of the larger public sites.

Six Apart’s TypePad AntiSpam plugin is the most interesting one, however, and I’ll be using it on an upcoming project to see how it turns out.

How do you battle comment spam on your blog, and how is the war coming along? Share your experiences in the comments.