There is nothing more frustrating than logging in to your WordPress admin page and finding dozens, if not hundreds of comments waiting for approval, only to find that the overwhelming majority of them are spam. The good news is that there are some great wordpress comment spam plugin techniques you can use to help sort the real comments from the trash.
Akismet is, in my opinion, one of the best spam plugins available. I’ve used their software for years to help sort the good from the bad. They do an excellent job of text-reading, which is the ability of software to compile a probabilistic profile on whether or not text has been generate by a human or a computer.
These techniques go a long way towards eliminating the “most obvious” spam, which I categorize as spam that includes excessively long comments, comments that are filled with extraneous links, or comments that include a number of non-word sequences.
However, Akismet does not do a great job at eliminating the more subtle spam, which might take the form of a general message that on first glance might look like a human writer (or perhaps a writer with non-native english) but really is generated by a software script. The biggest problem I’ve encountered here is if you approve one of these ‘subtle’ spam messages (many times they won’t contain links, making it hard for the anti-spam software to catch them), they can occasionally save the IP and/or email address used to post the message, and provide future, ‘spammier’ comments in the future.
While Akismet is still very effective, there was an unfortunate breach at the end of 2013, that some spam comments can now evade the plugins algorithm. If you’re already using Akismet and still suffering from an inordinate number of comments, I recommend you implement a CAPTCHA system as well.
The other technique to use is to enforce a CAPTCHA input from a user before they can insert a comment.
CAPTCHA’s are the fuzzy or obfuscated letters you’ll often see on comment forms, asking that a user input the word, phrase, or number shown in a box into the form field for approval. These designs, which often appear obvious to individuals, are extremely difficult for software scrapers, or bots, to navigate, since they are designed as pixillated images, rather than text or numeric characters.
The effect of using a CAPTCHA is that you enforce a human reader to enter the number, rather than allowing a comment input from any source. While these may be annoying to a user, and potentially effect the number of comments you get from real readers, the idea of deterring spam bots is attractive to many bloggers.
To use a CAPTCHA as a WordPress comment spam plugin, simply search for a relevant plugin form your wordpress directory, and then follow the instructions given to install and activate.
If you use these two plugins, you should see the number of spam comments diminish drastically on your site. Feel free to comment below if you have any other suggestions for blocking inappropriate or spam comments on your blog.