How to Fix Canonical Tags for SEO
Canonical tags are essential for ensuring that search engines understand which version of a URL is the authoritative or preferred one, preventing duplicate content issues and improving your website’s overall SEO performance. However, incorrectly implemented or missing canonical tags can cause significant problems, such as diluted link equity and poor rankings in search engine results pages (SERPs).
In this guide, we’ll cover how to fix canonical tags, why they are important, and best practices for implementing them correctly.
What Are Canonical Tags?
A canonical tag (also known as a rel="canonical" tag) is an HTML element that tells search engines which version of a URL you want to be indexed. If multiple URLs lead to the same content (due to URL parameters, pagination, or domain issues), the canonical tag consolidates these URLs into one preferred version.
For example:
<link rel="canonical" href="https://www.example.com/preferred-page.html">
This tag indicates to search engines that the URL https://www.example.com/preferred-page.html is the one that should be indexed and ranked in SERPs.
Common Issues with Canonical Tags
Before fixing canonical tags, it’s important to identify common mistakes that could be affecting your SEO:
- Missing Canonical Tags: Some pages may not have any canonical tags, leading to duplicate content issues when multiple URLs exist for the same content.
- Incorrect Canonical Tags: Pages may have the wrong canonical tag, such as pointing to an unrelated page or pointing to the wrong URL version (e.g.,
http://instead ofhttps://). - Canonicalizing the Wrong Version: Pointing all pages to the homepage or another irrelevant page (often called cross-domain canonicalization) can confuse search engines.
- Self-Referencing Canonical Tags: While it’s good practice to have self-referencing canonical tags, some websites fail to implement this, leaving search engines unsure of which version is preferred.
- Duplicate Canonical Tags: Having multiple canonical tags on the same page can cause errors in search engine processing.
Steps to Fix Canonical Tags
Follow these steps to identify and fix issues with canonical tags to improve your site’s SEO performance:
1. Conduct a Canonical Tag Audit
The first step is to audit your website to identify any issues with canonical tags. You can use SEO tools like:
- Screaming Frog: This tool allows you to crawl your website and detect missing or incorrect canonical tags. After a crawl, navigate to the Canonical section to review the current tags on each page.
- Google Search Console: Go to the Coverage section in Google Search Console to identify any indexing or duplicate content issues related to canonical tags.
2. Fix Missing Canonical Tags
If you find pages that don’t have canonical tags, add them manually or via your CMS. For example, if you’re using WordPress, you can use SEO plugins like Yoast SEO or Rank Math to automatically add canonical tags to your pages.
Here’s the code to manually add a canonical tag:
<link rel="canonical" href="https://www.example.com/page-url.html">
Make sure that the canonical tag references the correct, preferred version of the URL.
3. Fix Incorrect Canonical Tags
If a canonical tag points to the wrong page (e.g., to an old version of the page or the wrong protocol like http instead of https), you’ll need to update the canonical link in the HTML <head> section to reflect the correct URL.
Ensure the URL includes:
- The correct protocol: Use https:// instead of http:// if your site has an SSL certificate.
- The preferred domain: Use either www or the non-www version of your domain, depending on which you want to prioritize.
4. Use Self-Referencing Canonical Tags
Each page on your website should have a self-referencing canonical tag, even if there are no duplicate versions. This practice makes it clear to search engines which URL should be indexed.
Here’s how to set up a self-referencing canonical tag:
<link rel="canonical" href="https://www.example.com/page-url.html">
This tag tells search engines that the page should be indexed exactly as it appears.
5. Handle Pagination Correctly
Pagination (e.g., when blog posts or product categories span multiple pages) can cause duplicate content issues if canonical tags aren’t set up properly. Here’s how to handle pagination:
- Each paginated page should have a self-referencing canonical tag (e.g.,
page 2should have its own canonical tag). - Alternatively, you can use rel=”next” and rel=”prev” tags to inform search engines about the sequence of pages in a series. This way, search engines can properly index each page in the sequence.
6. Avoid Canonicalizing the Homepage
It’s a common mistake to point all pages to the homepage in an attempt to consolidate SEO signals. This approach is incorrect and can confuse search engines. Always point canonical tags to the most relevant URL, not the homepage, unless you are specifically resolving an issue with the homepage.
7. Use Canonical Tags for URL Parameters
Sometimes, URL parameters (such as session IDs, filters, or tracking codes) create different versions of the same page. Use canonical tags to tell search engines that the parameterized versions should be treated as duplicates of the main page.
For example:
<link rel="canonical" href="https://www.example.com/page-url.html">
This tells search engines that even though the URL may include parameters, the content is the same, and only the canonical URL should be indexed.
8. Test Your Canonical Tags
Once you’ve implemented or fixed your canonical tags, it’s important to test them. Use these tools:
- Google Search Console URL Inspection Tool: This will show you how Google is interpreting your canonical tags. Enter the URL and check the “Canonical” section to see which URL Google has chosen as the canonical version.
- Screaming Frog: After implementing changes, crawl your site again with Screaming Frog to verify that all canonical tags are correct and consistent.
Best Practices for Canonical Tags
To ensure your canonical tags are working properly and benefiting your SEO strategy, follow these best practices:
- Use Self-Referencing Canonical Tags: Every page should point to itself with a canonical tag, unless there is a specific reason to reference another URL.
- Use Canonical Tags Consistently: Make sure canonical tags are consistently applied throughout your site and point to the preferred version of each page.
- Check Canonical Tags Regularly: Perform regular SEO audits to ensure your canonical tags are functioning correctly and aren’t pointing to irrelevant pages.
- Handle Cross-Domain Canonicals with Care: If you need to reference a canonical URL across different domains (cross-domain canonicalization), make sure it’s necessary and implemented correctly to avoid SEO penalties.
- Use 301 Redirects When Necessary: In cases where you have permanent duplicate pages, consider using 301 redirects in combination with canonical tags to direct users and search engines to the preferred page.
Conclusion
Fixing and properly implementing canonical tags is essential for avoiding duplicate content issues and ensuring that your website’s SEO performance is optimized. By following the steps outlined above, you can effectively audit your site for canonical tag issues, implement fixes, and ensure that search engines correctly interpret your preferred URLs.
By paying close attention to how canonical tags are set up and following best practices, you’ll avoid common pitfalls, improve your site’s search engine visibility, and consolidate link equity to boost your search rankings.
