Duplicate content occurs when the same information is displayed verbatim in more than one location (URL). This can be an internal issue, i.e you have multiple pages or URLs on your website displaying the same information, or it can be an external issue, where the same content on your web pages is also available elsewhere.
Internal Duplicate Content
Because of the way website software such as WordPress works, it’s easy to have internal duplicate content issues, and rarely from human error.
A key example is WordPress’ tag pages. If you tag a post, a page is created at http://example.com/tag/tag-name. But if this page isn’t configured properly, the full post will show. This means you now have content displayed at two separate URLs, minimum (depending on how many tags you’ve added).
Duplicate problems like this won’t trigger search engine penalties, but your website might suffer from lack of clarity and optimization.
Search engines only include one URL for each piece of indexed content. When you have duplicate content, search engines decide which is the original. Search engines won’t necessarily know what’s best for your site or business, meaning their unnecessary work could damage your optimization.
It is also important that the most important page acquires as much page authority as possible, rather than being spread between multiple pages.
Rectify duplicate content by using the canonical tag.
Canonical URLs
Canonical URLs were introduced in 2009 and apply to all three major search engines. Rand Fishkin from SEOmoz called this “The Most Important Advancement in SEO Practices Since Sitemaps“.
Canonical tags are placed in the <head> of your website and tell the search engines the URL which is the original, should receive the link juice and be listed in the search engines.
Example URL: <link rel="canonical" href="http://outstandingseo.com/search-engine-optimization>
External Duplicate Content
External duplicate content is when you have content on your web page that is identical to the content on another web page. This is far more serious since it means one site has plagiarized another. This type of duplicate content can result in penalties.
Note: a couple of pages can be excused, as there are many legitimate reasons to have a few pages of unoriginal content, but if your whole site is copied, you have a major problem.
If content is original to you, don’t waste time worrying if others are stealing it. In our experience, search engines are extremely good at finding the original. However, if you do come across this problem, you can report the mistake.
