How to prevent comment spam

Just as you can get spam messages in your inbox, people (or more often bots) will leave spam comments with unsolicited advertising on your website blog or comment fields. However unlike email spam where you are the target, comment spam generally targets search engines.

Comment spam refers to a broad category of spambot or spam postings which abuse web based forms on websites. Unsolicited advertisements are posted as comments on forums, blogs, wikis and online guestbooks.

Why are they spamming me?

Spammers want to get better search rankings or lure unsuspecting visitors to dubious and malicious sites. By spamming they attempt to get more links and therefore positively affect their site’s search rankings.

In most cases, it is not a personal attack against you; rather it’s a systematic process that targets many blogs, using automated spambots.

Effects of comment spam

The effects of comment spam are usually high server load and large database tables, which can have a detrimental effect on all users on a shared server.  For this reason comment spam contravenes our Acceptable Use Policy and website owners need to put measures in place to ensure that comment spam is minimised.

This type of spam can be harmful to your site in several ways including:

  • Low-quality content (ie.s spam) on some parts of a website can impact the whole site’s Google rankings.
  • Spam can distract and annoy your users and lower the reputation of your site.
  • Unintended traffic from unrelated content on your site can slow down your site and raise bandwidth costs.
  • Google might remove or demote pages overrun with user-generated spam to protect the quality of our search results.
  • Content dropped by spammers can lead to malicious sites that can negatively affect your users.

How to prevent comment spam

Add Google reCAPTCHA


ReCAPTCHA is an advanced form of CAPTCHA, which is a technology used to differentiate between robots and human users. CAPTCHA is an acronym for “Completely Automated Public Turing test to tell Computers and Humans Apart”.

Google makes it easy for users to verify their identity by simply clicking on the checkbox button.

For spambots, this technology is quite hard to bypass because when Google detects a spam bot, it gives them a much harder challenge.

Use plugins for WordPress sites



For more, see: Ways to prevent comment spam