Virtually every SEO agency offers a core set of services. They include things like keyword research and on-page optimization. Then there are more advanced techniques that might be incorporated into standard services or offered as extra options. Canonicalization is one such technique.
Do you know what canonicalization is? Do you know how it applies to modern SEO? If not, you are in luck. This post will explain it in the simplest possible terms. Just know that this is a technique every SEO agency should be practicing at this point. The web has become so vast and convoluted that canonicalization is crucial to SEO success.
The Basic Premise of Canonicalization
Canonicalization is built on a simple premise: multiple URLs offering duplicate or similar content confuse web crawlers. They create problems for search engine algorithms trying to figure out the best pages to serve up. Canonicalization essentially tells a web crawler which version of the similar content to use. This version becomes the canonical version for search purposes.
The technique is crucial to modern SEO due to the fact that search engines do not appreciate duplicate content. In some cases, they even punish it. But from a web developer’s standpoint, overcoming the duplicate content issue isn’t as easy as deleting a page or two. There are valid reasons for duplicate content, reasons that would be subverted if pages were simply deleted.
How Canonicalization Works
As an SEO agency, we are tasked with making sure that all the major search engines can crawl, analyze, and properly rank the pages we produce. Our clients do not want excuses. They want results. Sometimes that means employing canonicalization.
The most common way to deal with duplicate content is to use a canonical tag embedded in the <head> section of the page. This tag tells web crawlers that the page they are looking at is the authoritative version of the content in question. There are two other options:
- Listing a canonical URL in the HTTP response header; and
- Listing the preferred URL on the website’s XML sitemap.
In all three cases, you are giving explicit instructions to web crawlers indicating which version of the content should be considered the canonical version. Other versions are then ignored for ranking purposes. As far as web crawlers are concerned, those other versions do not exist.
One last thing to consider before moving on is the ease through which canonical tags are applied. If you are handling your own site and SEO through a content management system (CMS), check the platform’s documentation to see if canonical tags are something you can implement on your own. Organizations working with an SEO agency can send a quick message and let the agency handle implementing the tags.
4 Reasons for Implementing Canonicalization
Now that you know what canonicalization is, it is time to discuss why SEO agencies should implement it. As we see it, there are four reasons:
- Preventing issues that arise when duplicate and similar content confuse web crawlers.
- Improving crawl efficiency, thereby helping search engines prioritize important content.
- Ensuring that ranking power is concentrated by focusing crawlers on the correct pages.
- Proper management of content found in multiple versions on the same site.
Canonicalization becomes more important as a website grows. The larger a site becomes, the more likely it is to contain duplicate content. Without canonicalization, it would be nearly impossible for search engines to make sense of the largest sites on the web. For that reason alone, every SEO agency should have a firm grasp of the technique and its implications.
