Canonical Tag: What is it and why it matters

Last Updated April 22, 2024

Today, we are going to talk about a term that is crucial for your blog’s SEO – the Canonical Tag.

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What is a Canonical Tag?

A canonical tag, also known as rel=canonical, is a piece of HTML code that helps search engines identify the main version of a page when there are multiple pages with identical or very similar content.

In simpler terms, it’s a way to tell search engines, “Hey, this is the main version of this page that I want you to index and show in the search results.”

For example, the canonical tag for your main blog page might look like this:

<link rel="canonical" href="https://yourblog.com/main-page/" />

Why Are Canonical Tags Important?

Avoid Duplicate Content: Search engines, like Google, don’t like duplicate content. It confuses them, and they might end up indexing and ranking the wrong version of your page. Canonical tags help you specify which version of the page you want to be considered as the main one.
Consolidate Link Equity: If there are multiple versions of a page, the backlinks to those pages will be divided among them. By using a canonical tag, you consolidate the link equity to the main page, which can help improve its ranking.
Improve Crawling Efficiency: Search engines have a crawl budget, which is the number of pages they will crawl on your site in a given time. By using canonical tags, you can help search engines to not waste their crawl budget on duplicate pages.

Best Practices for Using Canonical Tags

Use Absolute URLs: Always use the absolute URL in the canonical tag, not the relative URL. For example, use https://yourblog.com/main-page/ instead of /main-page/.
Self-Canonicalize: Even if a page doesn’t have any duplicates, it’s still a good practice to include a self-referencing canonical tag. This helps to avoid any confusion for search engines.
Be Consistent: Make sure that the URL used in the canonical tag is consistent across the site. For example, if your site uses https, make sure that the canonical tag also uses https.

Common Mistakes to Avoid

Canonical Chains: A canonical chain occurs when Page A references Page B as the canonical, and Page B references Page C as the canonical. Always point the canonical tag directly to the main version of the page.
Multiple Canonical Tags: There should only be one canonical tag on a page. If there are multiple canonical tags, search engines might ignore them.
Non-Similar Content: Don’t use the canonical tag on pages with completely different content. It should only be used on pages with identical or very similar content.

Conclusion

Canonical tags are an essential tool for bloggers to manage duplicate content, consolidate link equity, and improve crawling efficiency. By using them correctly, you can help search engines understand your content better and improve your blog’s SEO.

Do I need a canonical tag if I do not have duplicate pages?

Yes, it is still a good idea to add a self-referencing canonical tag on each page.

A self-canonical tag tells Google, “This exact URL is the main version.” That helps prevent confusion if your page can be reached from more than one link, like with tracking parameters or different URL formats.

It also protects you if your site later creates a second version of the same page, like an HTTP and HTTPS version, or a version with and without a trailing slash.

If you are not sure which URL format to use, pick one clean version and stick with it across your site. A consistent permalink structure also makes internal links and indexing more reliable.

What is the difference between a canonical tag, a 301 redirect, and a noindex tag?

A canonical tag tells search engines which page should be treated as the main version, but it still allows other versions to exist.

A 301 redirect sends both users and search engines from one URL to another. Use a redirect when you want the old page to be gone and replaced, like after changing a URL.

A noindex tag tells search engines not to index a page at all. That is useful for thin pages, duplicate filter pages, or private content you do not want in search results. See the Noindex tag guide for examples of when it makes sense.

In many cases, canonical is best when you need duplicates for users, like printable pages or tracking URLs, but you want only one version ranking.

When should I use a canonical tag on my blog?

Use a canonical tag when the same or very similar content can show up on more than one URL.

Common cases include URL parameters like ?ref=, category or tag pages that repeat excerpts, and pages that can load with both www and non-www versions. Another common issue is a page that works with and without a trailing slash.

Canonical tags are also helpful for e-commerce style sorting and filtering pages, where many URLs show almost the same content. The goal is to point all versions back to the one page you want indexed.

If you also want to help Google find your main pages faster, make sure your site has a clean sitemap and submit new URLs when needed. The Submit for indexing guide can help with that workflow.

What happens if I have multiple canonical tags or a canonical chain?

If a page has more than one canonical tag, search engines may ignore them or choose the wrong one.

A canonical chain happens when Page A points to Page B, and Page B points to Page C. This can weaken your signal and slow down how search engines decide what to rank.

The fix is simple: use only one canonical tag per page, and point it directly to the final main URL. Also make sure the canonical URL matches your preferred format, like HTTPS and the correct trailing slash.

After you fix it, re-check a few pages to confirm the canonical in the HTML matches what you intended. Consistency is what helps Google trust your choice.

How can RightBlogger help me improve SEO when using canonical tags?

RightBlogger can help you spot SEO issues around duplicates and page versions by making your on-page SEO easier to review and improve.

If you publish often, it is easy to create near-duplicate intros, similar headlines, or multiple URLs for the same topic. Running an audit with SEO Reports helps you catch common problems before they hurt rankings.

You can also refresh older posts so the main version is clearly the best version. Tools like Auto Optimize can help you tighten titles, headings, and keyword use so the canonical page is the strongest one.

If you publish to WordPress, using the WordPress integration can save time and reduce mistakes when updating pages, URLs, and SEO settings.