Demystifying Canonical Tags in SEO: A Non-Technical Guide

In the world of SEO, one term that often crops up is “canonical tag.” For those not well-versed in the intricacies of search engine optimisation, this term might sound like complex jargon. However, understanding canonical tags is crucial for website owners and marketers alike, especially when dealing with issues related to duplicate content. In this non-technical guide, we’ll demystify canonical tags, explain their significance, and provide real-world examples using an e-commerce website.

What Are Canonical Tags?

Imagine you have a favourite book, let’s call it “The Ultimate Guide to SEO.” This book is so popular that it’s available in various editions, such as hardcover, paperback, and e-book. While the content remains the same, each edition comes in a different format. This is fine when it comes to Books, but Google doesn’t like duplicates of the same content. Canonical tags are like bookmarks in your digital library, helping search engines understand which edition is the main reference for a particular topic.

In simpler terms, a canonical tag is a snippet of HTML code that tells search engines which version of a web page is the preferred, “canonical” version. This helps prevent duplicate content issues and ensures that search engines prioritise the right page when ranking and displaying results.

The Peril of Duplicate Content

Before we delve deeper into canonical tags, let’s talk about the menace of duplicate content. Duplicate content refers to identical or substantially similar content that appears on multiple web pages within the same website or across different websites.

Duplicate content can arise for various reasons, some of which are unintentional:

• Printer-Friendly Pages: Some websites offer printer-friendly versions of their web pages, which may contain the same content as the origina
• Session IDs: E-commerce websites often use session IDs to track user interactions, which can result in multiple URLs with the same content.
• URL Variations: Minor differences in URLs, such as uppercase vs. lowercase letters, trailing slashes, or URL parameters, can create duplicate content.
• www vs. non-www: Websites accessible with and without the “www” prefix can sometimes display the same content.
• Product Filters: E-commerce sites frequently allow users to filter products, potentially generating numerous URLs with similar product listings.

The Duplicate Content Dilemma for E-commerce

Let’s illustrate the duplicate content issue with an example from the world of e-commerce. Consider an online shoe store, “Shoe Paradise,” that sells a vast range of shoes. They have a category page for “Running Shoes,” and this is where the trouble begins.

Scenario 1:

• URL: www.shoesparadise.com/running-shoes/
• Description: A page displaying a wide selection of running shoes for men and women.

Scenario 2:

• URL: www.shoesparadise.com/running-shoes/?sort=price-asc
• Description: The same running shoe category page but sorted by price in ascending order.

Scenario 3:

• URL: www.shoesparadise.com/running-shoes/?color=blue
• Description: The same running shoe category page, but this time filtered to show only blue running shoes.

Scenario 4:

• URL: www.shoesparadise.com/running-shoes/mens/
• Description: A page displaying running shoes exclusively for men.

In each of these scenarios, the core content—running shoes—is essentially the same. However, the URLs differ due to sorting options, filters, or categories. Search engines might perceive these as distinct pages with duplicate content, which can harm SEO efforts.

This is where canonical tags come to the rescue.

Canonical Tags: The Problem Solvers

Canonical tags, denoted in HTML as <link rel=”canonical” href=”URL”>, act as a friendly signpost for search engines. They point to the preferred, canonical version of a page, signalling that it’s the primary reference for a particular topic or content.

Returning to our Shoe Paradise example, the webmaster can add a canonical tag to each scenario, indicating the main, canonical URL. Here’s how it works:

• Scenario 1:
  • Canonical Tag: <link rel=”canonical” href=”www.shoeparadise.com/running-shoes/” />
• Scenario 2:
  • Canonical Tag: <link rel=”canonical” href=”www.shoeparadise.com/running-shoes/” />
• Scenario 3:
  • Canonical Tag: <link rel=”canonical” href=”www.shoeparadise.com/running-shoes/” />
• Scenario 4:
  • Canonical Tag: <link rel=”canonical” href=”www.shoeparadise.com/running-shoes/” />

In this setup, all scenarios point to the main “Running Shoes” category page as the canonical version. Search engines take note of this and understand that while there are variations of this page, the primary content reference is the canonical URL.

How to Check for Duplicate Content and Canonical Tags

Now that you understand the concept of canonical tags, you might wonder how to identify duplicate content and check if canonical tags are correctly implemented. Here’s a step-by-step guide:

Step 1: Identify Duplicate Content

• Manual Inspection: Start by manually inspecting your website’s pages. Look for instances where content appears to be duplicated, such as similar product listings, category pages with different sorting options, or printer-friendly versions.
• Use SEO Tools: SEO tools like Screaming Frog, SEMrush, and Ahrefs can help identify duplicate content issues. They often provide reports highlighting duplicate title tags, meta descriptions, or URLs.

Step 2: Examine Canonical Tags

• View Page Source: You can view the HTML source code of a web page by right-clicking on it and selecting “View Page Source” (the exact option may vary depending on your browser). Look for <link rel=”canonical” href=”URL”> within the <head> section.
• SEO Tools: Many SEO tools offer features to check canonical tags on a website. Simply enter the URL of a specific page, and the tool will display whether a canonical tag is present and where it points.
• Google Search Console: If you have access to Google Search Console for your website, it provides insights into duplicate content issues and the correct implementation of canonical tags.

Step 3: Verify Canonical Tags’ Accuracy

Once you’ve identified duplicate content and examined canonical tags, it’s essential to ensure that the canonical tags are correctly implemented. Here’s what to look for:

• Verify that the canonical tag on each page points to the appropriate canonical URL. It should accurately represent the main reference for that content.
• Double-check that canonical tags are present on all relevant pages, particularly on pages with duplicate content issues.

Wrapping Up

Canonical tags might sound like a technical headache, but they are a valuable tool in your SEO arsenal, especially when dealing with duplicate content on your website. Understanding their purpose and correctly implementing them can significantly benefit your website’s rankings and overall SEO performance.

In essence, canonical tags are like signposts that guide search engines to the main source of content, helping prevent confusion and ensuring your web pages appear in search results as intended. By addressing duplicate content issues with canonical tags, you can enhance your website’s SEO health and provide a better user experience for your visitors.

If you fancy a few more SEO tips, or need some help with your SEO Strategy  feel free to give us a call on 0117 930 4365 or drop us an email.