Duplicate Content and Canonical Tags: A Refresher
by Geoff Hineman
It seems we can't go a month without Google announcing some major change that has us wondering about how we need to factor that change into our SEO processes. Some changes make life easier. Some do not. Fortunately, SEOs have a substantial list of evergreen fundamentals that form a real bedrock for planning, despite most new changes to ranking factors.
One of the fundamental aspects of SEO that can be executed by even the rookie SEO is handling duplicate content. In this post, we will revisit what duplicate content is, why it is problematic, and go over a couple of ways to fix it, including canonical tags.
What is Duplicate Content?
Duplicate content occurs when two or more pages features copy and coding so similar that search engines deem them duplicates. This can happen for several reasons, but the two most common are:
- Very little copy on the page and nearly the same coding that renders the look and functionality of the page
- A product page features the same product as other pages, but with a very slight variations (e.g., sizes, colors, etc.)
Maybe you have heard the term "duplicate content penalty" bandied about in the past. While duplicate copy does undermine your ability to rank better, it is not currently subject to any penalties from search engines.
When search engines find duplicate pages, it becomes a real coin toss as to which page to return in the results. Since they both look the same, the value of the page will be split by the number of duplicate pages. For instance, if you have two duplicate pages, the value of each would be one half of what a non-duplicated page would be. If you have four duplicate pages, each page will get one-quarter the value of a single page. This division of value is what can cause ranking problems, not an actual penalty like you would get for buying or selling links.
For pages that fall into the category of being different pages with little-to-no copy, the simplest solution is to implement additional, unique copy to each page. In doing so, you can create enough variation between the pages that search engines can then tell what the differences between the pages are.
The other option, which is particularly useful to e-commerce sites is implementing canonical tags.
What Are Canonical Tags?
Canonical tags are snippets of code to show search engines that certain pages are duplicates of another and to take that other URL as the main URL.
For instance, if you have four products that are all the same except for the size and they each have their own URLs, you'd have something that looks like this:
Without canonical tags in place, Google would divide the value of these pages by four, thus giving each page one-quarter the value of a single page. With canonical tags, however, we can tell Google to give all the value to the one page we choose, because they others are just variations of the one page.
If we wanted to designate product A as the main product, then the canonical tags in the code of all the pages would look like this:
Most e-commerce platforms come with the ability for you to establish the canonicals so you don't have to get your hands dirty in the coding. There are also several third-party tools, such as Moz and ahrefs that can identify your duplicate content pages.
Duplicate content is a quiet killer for website rankings. Still, there are tried and true methods for countering it. Whether it's crafting additional copy to distinguish these pages or implementing canonical tags to direct Google's attention, you have options. Barring some complete overhaul in the way Google crawls, indexes, and ranks pages, these methods should get you well on your way to improved rankings and increased traffic.