Canonical tags

Canonical tags are an important tool in technical SEO for avoiding duplicate content and telling search engines which version of a page should be treated as the original and preferred one. These tags help to concentrate all SEO authority on the preferred URL instead of spreading the ranking across several similar or identical pages. Canonical tags are particularly useful for e-commerce websites or websites with many similar pages created by filters or sorting options.

Why canonical tags matter for technical SEO

• Avoiding duplicate content: Canonical tags stop search engines from indexing identical or very similar content on several URLs, which could lead to a downgrade in SEO value.
• Better distribution of SEO authority: The canonical tag ensures that SEO authority is concentrated on the main URL instead of being spread across several versions of the page.
• Ensuring correct indexing: Search engines receive clear instructions on which URL should preferably be indexed and shown in the search results.
• Optimising crawl efficiency: By using canonical tags, you direct crawlers to the relevant pages and so optimise the use of the crawl budget.

Best practices for canonical tags in technical SEO

• Correct use of the canonical tag: Implement the canonical tag in the <head> section of the page to make sure search engines interpret it correctly.
• Avoiding internal duplicates: Use canonical tags to prevent different URLs on your website (e.g. from session IDs, sorting or filters) from being indexed as separate pages.
• Self-referencing canonical tags: If a page is the preferred version, it should point to itself as the canonical version.
• Keep URLs consistent: Make sure the canonical tag uses the exact URL you prefer, including the correct use of “www” or “https”.
• Regular checks: Use SEO tools such as Google Search Console to make sure canonical tags are implemented correctly and do not cause errors.

Conclusion

Canonical tags are a central element of technical SEO for avoiding duplicate content and concentrating SEO authority on the right URL. By implementing canonical tags correctly, you ensure that your website is crawled efficiently by search engines and displayed correctly in the search results.