Accidentally creating duplicate content in Drupal is like… catching a cold: 

It’s as easy as falling off a log.

All it takes is to:
 

• further submit your valuable content on other websites, as well, and thus challenging Google with 2 or more identical pieces of content
• move your website from HTTP to HTTPs, but skip some key steps in the process, so that the HTTP version of your Drupal is still there, “lurking in the dark”
• have printer-friendly versions of your Drupal site and thus dare Google to face another duplicate content “dilemma”
   

So, what are the “lifebelts” or prevention tools that Drupal “arms” you with for handling this thorny issue?

Here are the 4 modules to use for boosting your site’s immunity system against duplicate content.