Best Practices for Canonical Tags

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• What Is a Canonical Tag?
• How Do Canonical Tags Affect SERPs?
• What Are the Best Practices When Using Canonical Tags?

When a search engine crawls your website, having duplicate pages can lower the ranking of your new content. That’s why it’s so important to use canonical tags on all of your URLs that go to the same webpage. In order to do this, you need a good understanding of HTML and search engine optimization (SEO). Let’s further explore the importance of this duplicate content solution.

What Is a Canonical Tag?

A canonical tag is a way for you to tell search engines that a single URL is the master copy of a webpage. The purpose of a canonical tag is to make sure search engines like Google only display your intended URL on their search engine results page (SERP).

Basically, there are many reasons you may have duplicate content for an original page. The canonical tag solves this problem by identifying what that original page is. Here are some scenarios where you may have duplicate pages on your website:

• Filter options — E-commerce websites tend to have filters for colors, sizes, styles, and other factors that sort their products. Each one of these filters can create duplicate URLs.
• Session IDs — Many duplicate URLs are created by the systems you use. For instance, print versions of pages, tracking URLs, and breadcrumb links can all create duplicates.
• HTTP, HTTPS, and WWW — Although all of these will lead to the same webpage, a search engine doesn’t necessarily know that and will crawl each version.
• Case — If you use a mix of lowercase and uppercase letters for folder and file names, a search engine may crawl both versions.
• Mobile — If you have a mobile website, you may have “m.” at the beginning of your mobile URL.

Image via Unsplash by thisisengineering

How Do Canonical Tags Affect SERPs?

Canonical tags ensure that only one URL is displaying a particular webpage. Even if you didn’t intentionally create a duplicate page, Google considers every unique URL to be a new webpage, even if multiple URLs all lead to the same page. For example, the following URLs could all lead to the About page on your website:

• https://www.example.com/about
• https://example.com/about
• http://example.com/about

The downside of Google crawling all of these versions of basically the same URL is that they may all show up on the SERP for your website. This affects your SEO because users will only see these duplicate pages and not any of the new, unique content you want to share. By using the canonical tag, you can choose one of those URLs to show up on a SERP. Likewise, using this tag can help you direct users to the intended, clean-looking URL you want to use for a particular page.

The canonical tag is especially important for websites that have syndicated content. You can use the tag to ensure that your website’s page ranks at the top rather than your publisher’s. This is also helpful if another website were to plagiarize your content. You could try to get the tag on your website to ensure your page ranks over the other website. If the stolen page got any backlinks, it would benefit your page, which is the original.

What Are the Best Practices When Using Canonical Tags?

When dealing with duplicate content, it can become quite a mess. This is especially true if your CMS is responsible for creating dozens or even hundreds of duplicate webpages. When using canonical tags to clean up your SERPS, follow these best practices:

• Audit your canonical tags — Periodically audit your canonical tags to ensure they are helping your SEO performance. Check if your pages have a canonical tag, if the tag is directing to the correct page, and if the pages are able to be indexed or crawled. Using SEO site audit software can make this process much easier.
• Use them for their intended purpose — Some webmasters try to be sneaky and use canonical tags to manipulate their rankings on specific keywords. Only use canonical tags to fix duplication issues or else Google will see through what you’re trying to do and won’t rank you favorably.
• Update them when you upgrade from HTTP to HTTPS — If not, you could risk having your canonical tag point back to the HTTP version. If you have redirects set, this can redirect Google to the HTTPS version and confuse the algorithm. You may risk an unending loop, which may result in an error message.
• Know when to use a 301 redirect vs. a canonical tag — Both are not a one-size-fits-all solution. Though they do similar things, they have different end results. Basically, a 301 redirect tells a web browser to redirect a specific page so that users never see it. A canonical tag ensures that Google only shows the intended page you want on a SERP. However, if the user were to type in the URL, they could still view this page. By using a 301 redirect on accident, you could risk users never seeing one of your URLs.
• Keep your tags organized — When you fail to add canonical tags in the right order, Google may become confused with your intentions, which can mess up your rankings. Make sure you don’t accidentally point two pages at each other. Likewise, creating a chain of canonical tags may confuse search engines. Page A to Page B, Page B to Page C, and Page C to Page D may be too much for the algorithm to process and may not work out correctly for your website.

In order to follow search engine optimization best practices, it’s important to use the canonical tag to let search engines know which content to crawl. Following this advice can help you improve your SEO and get more meaningful web traffic.

Knowledge Base: SEO