How to spot duplicate content issues

[AdamLee]

I'm using the pear analytics tool to run a quick test on the SEO health of my site.

It came back with duplicate content issues. How can I identify where the duplicate issues are and how can I resolve them?

If anyone has a link to a post that'll help that would be great.

[Stevie D]

A common cause of 'duplicate content' is where you have multiple versions of the same URL.

If Google has indexed all of
domain.com/
domain.com/index.htm
www.domain.com/
www.domain.com/index.htm
separately, that could give you a problem, because it is treating them as four separate pages, rather than as four routes to the same page.

What should happen is that whichever one you type into the address bar, it gets corrected to your preferred format. It doesn't matter which of them it is (although it's good practice not to include 'index.htm'), as long as it's consistently applied throughout the site and each actual page only shows up with a single URL.