In this article, I will share one or more valuable tips to combat spam comments in WordPress.
The rate at which people / bots spam now is very high, now in this method, it’s more or less like pretending to be a bot to catch a bot. Here is the full overview:
Invisible Defender is a WordPress plugin, which protects registration, login and comment forms from spambots by adding two extra fields hidden by CSS. This approach can give you up to 100% anti-spam protection on your sites.
The idea behind this plugin is simple: SPAMBOTs either fill every form field they find (generic spambots) or fill WordPress-specific fields only (spambots which will recognise WP or are targeting WP only). Therefore it is sufficient to add two extra text fields to form (one empty and one with predefined value), and check theirs values after form is submitted. 1st field (empty one) will be filled by generic spambots, and 2nd one will not be filled by spambots targeting WP only. With these two simple checks probably all spambots can be easily detected, so WP can return error “403 Forbidden” for them.
These two extra fields are hidden with CSS rule, so they will not be visible for most users. Only users with text-based browsers (and very old ones which not support CSS) will see them, but don’t be afraid – plugin has special message for them.
Invisible Defender also shows number of blocked spammers in Dashboard, so you can see that it really works.
You can download this plugin from wordpress.org site.
Other methods to try includes:
Nofollow Comment Links
Reduce Comment Spam Using Cookies
Block Spam Comment Bots Using Honeypot
Add Captcha Verification
Removing Website URL Field from Comment Form.