Canonicalization involves selecting the “primary” or “preferred” URL for a page. A canonical tag signals to search engines that it’s the main version among multiple similar versions. Other URLs with the same content are seen as duplicates and should be disregarded. To indicate that a URL is canonical, you should add canonical tags to all duplicate pages. Let’s dive into what a canonical tag is and why it’s important.
What Is a Canonical Tag?
A canonical tag (rel=“canonical”) is an HTML element that helps search engines identify the preferred URL when multiple URLs feature similar or duplicate content. Here’s an example of how the code looks:
<link rel=“canonical” href=“https://drvsasexperiment.com/home/” />Why Are Canonical Tags Important?
When search engines encounter multiple URLs with similar content, they may classify them as duplicates, potentially harming your site’s ranking. Additionally, too many URLs can overwhelm your site’s crawl budget, wasting search engine resources on unnecessary pages. There’s also a risk that a less preferred version might appear in search results instead of the main one. Canonical tags help prevent these issues by directing search engines to the correct URL.
Examples of Duplicate URLs
Consider an e-commerce site with multiple URLs leading to the same content:
- Main URL: https://footwearshop.com/running-shoes/nike-air-zoom
- Category variation: https://footwearshop.com/nike/nike-air-zoom
- Layered navigation:
– https://footwearshop.com/running-shoes/nike-air-zoom?color=red
– https://footwearshop.com/running-shoes/nike-air-zoom?size=10 - Protocol variations:
– http://footwearshop.com/running-shoes/nike-air-zoom
– https://www.footwearshop.com/running-shoes/nike-air-zoom - Parameterized URLs:
– https://footwearshop.com/running-shoes/nike-air-zoom?utm_source=newsletter
All these URLs display the same content as the main page. To specify the preferred URL, place a canonical tag in the header:
<link rel=“canonical” href=“https://footwearshop.com/running-shoes/nike-air-zoom” />What Happens If You Don’t Specify a Canonical URL?
Without a canonical tag, Google will determine the canonical URL based on factors such as sitemap entries, internal links, redirects, and user engagement.
How to Add Canonical Tags
Place the canonical HTML code in the <head> section of each duplicate page. It’s also advisable to add a self-referencing canonical tag to the main page. SEO tools like RankMath and Yoast SEO can help you add these tags easily without manual coding.
Canonical Tags vs. 301 Redirects
Use canonical tags when you want multiple URLs to exist but want search engines to recognize one as the main page. Use 301 redirects when you want to permanently move a page and make it inaccessible.
Canonicalization Best Practices
- Add self-referencing canonical tags on canonical pages.
- Always canonicalize URLs with parameters.
- Don’t use canonical tags on pages with completely different content.
- Only use one canonical tag per page.
- Ensure canonical URLs are indexable and ideally the only ones in your sitemap.
- If a duplicate page isn’t needed, consider using a 301 redirect instead.