Google's SEO Tip: Fixing Issues with Canonical URLs

Google’s John Mueller recently shared advice on LinkedIn for helping Google select the correct canonical URL, an essential factor for SEO. When Google ranks the wrong URL, it can impact search visibility and user experience by highlighting a less relevant version of a page. Mueller explained that while Google tries to automatically choose the best canonical URL, it sometimes doesn’t align with what website owners intend.

Mueller advised that SEOs and publishers can take steps to guide Google’s decision on this front. One key recommendation is ensuring the canonical tag points to the desired URL across the site. He also suggested making consistent use of internal links and sitemaps to signal to Google which version is preferred. Implementing these elements consistently helps Google interpret the intended structure of the website more accurately.

By following these steps, SEOs can improve the likelihood of Google selecting the correct URL as canonical. Addressing canonical misalignment is especially useful for larger sites with duplicate or similar content, as it can consolidate page rankings and improve search performance. Mueller’s advice highlights a proactive approach for maintaining accurate search results and improving site optimisation.

What Is A Canonical URL?

In cases where multiple URLs share identical content, Google selects one URL to represent all similar pages, known as the canonical URL. To help Google identify the preferred URL, Google Search Central has outlined several methods that SEOs and publishers can use to communicate their preference. While these techniques serve as suggestions rather than definitive instructions, they provide valuable signals to guide Google’s choice.

Three primary methods exist to indicate a preferred URL. First, redirecting duplicate pages to the chosen URL provides a strong signal to Google. Second, using the `rel=canonical` link attribute on duplicate pages indicates the preferred URL and acts as another strong signal. Finally, listing the preferred URL in the website’s sitemap is also a useful approach, though considered a weaker signal by Google. However, it’s important to note that these techniques only suggest the preferred URL; Google ultimately makes the final selection.

Some terminology within Google’s canonicalization documentation may lead to misunderstandings. For instance, while the `rel=canonical` is frequently called a link element, it’s actually an attribute of the HTML link element (`<link>`). Google sometimes also calls `rel=canonical` an annotation, which might be used internally but is not an official HTML term.

In HTML, understanding elements and attributes is essential. Elements serve as the foundational blocks of a web page, while attributes add further details about those elements. According to the Mozilla Developer Network (MDN), which is an authority on HTML specifications, `<link>` is an HTML element, and `rel=` functions as an attribute of that element, helping to clarify the distinction for SEO and web development purposes.

Person Read The Manual But Still Has Questions

After reviewing Google’s documentation on canonical URLs, a LinkedIn user sought clarification, expressing confusion about how Google interprets canonical signals. Referring to the documentation simply as “doc,” the user outlined the recommended approaches for signalling a preferred URL, including the use of the `rel=canonical` tag in the `<head>` section and listing preferred URLs in a sitemap. The question focused on why some URLs in the sitemap are still flagged as “Duplicate without user-selected canonical,” despite their presence in the sitemap, which the user expected would designate them as the canonical URLs for the site.

The user’s question highlights a common misconception about how Google interprets canonical hints from sitemaps. Although the sitemap helps Google understand preferred URLs, Google treats sitemaps as a weak signal in determining the canonical page. Stronger signals include redirecting duplicate pages directly to the preferred URL or using the `rel=canonical` link attribute within the page itself. The documentation emphasises that sitemaps are supplementary and often secondary to these stronger indicators, meaning that including URLs in the sitemap doesn’t necessarily ensure Google will select them as canonical.

Google’s approach to canonical selection considers multiple signals to make its decision. The process doesn’t rely solely on one factor but rather combines signals to select the URL it believes best represents a page’s content. Thus, even when URLs are listed in the sitemap, Google may still identify other URLs as canonical if other signals are stronger. This layered approach explains why some URLs still appear as “Duplicate without user-selected canonical” even when they’re included in the sitemap, underscoring the importance of using multiple, robust methods for canonical specification.

Google Uses More Signals For Canonicalization

John Mueller’s response sheds light on Google’s approach, highlighting that the search engine uses additional signals beyond what is officially documented when choosing a canonical URL. He clarified:

“If Google’s systems detect that pages are similar enough to consolidate focus on one, we then apply the factors mentioned in the documentation—alongside other internal signals—to decide which one to prioritise.”

This explanation indicates that Google’s selection process is more complex than it might seem from official guidelines alone. Rather than relying solely on documented methods, Google’s system considers a broader set of criteria to determine the most relevant URL when content duplication is detected.

Internal Linking Is A Canonical Factor

John Mueller also highlighted that internal linking strategies play a critical role in signalling a preferred URL to Google. This can help make it clearer to Google’s systems which URL should be prioritised when duplicate content or similar pages exist. Mueller advised webmasters and SEO practitioners to make this preference “very obvious” across their website. His suggestion includes setting a clear preference through a consistent internal linking approach, implementing a `link-rel-canonical` tag in the head section, and ensuring that sitemaps align with this preferred URL. He emphasised that creating a uniform message with all signals helps reinforce which page should be treated as canonical.

He further clarified that, from a search engine perspective, Google generally treats similar pages as equally valuable for search visibility, meaning that which URL appears in search results may not significantly affect a page’s search ranking or performance. However, the choice of URL can matter for the user experience and for the site owner’s tracking and analytics purposes. When Google’s systems select a particular URL, users may find it easier to navigate, and site owners can track performance or engagement more accurately with consistent URLs.

In this response, Mueller also implied that Google’s canonicalisation process considers various additional factors beyond what is officially documented. Even though sitemaps and canonical tags are essential, Google uses a broader range of signals to determine which URL to highlight, especially when the site has pages with overlapping content. This approach gives site owners the flexibility to influence Google’s choice, though Google’s systems ultimately decide based on multiple factors.

The takeaway from Mueller’s advice is that for webmasters and SEOs aiming to establish a clear URL preference, utilising all available signals effectively—internal links, canonical tags, and sitemaps—creates a stronger alignment with Google’s ranking algorithms. While the choice of URL may seem minor, a cohesive approach can benefit the website’s tracking and user experience consistency.

Takeaways

In my experience, it is common for large websites to have outdated internal links that point to incorrect URLs. In some cases, the issue arises not from these old links, but from 301 redirects leading from an old page to a URL that isn’t the preferred canonical version. This can result in Google selecting a URL that the publisher does not want to prioritise.

If Google is picking the wrong URL, it may be beneficial to conduct a comprehensive crawl of the site using tools like Screaming Frog. This allows for a detailed analysis of the internal linking patterns and redirects. Often, there may be overlooked internal links buried deep within the site or a chain of redirects leading to the wrong URL, which could influence Google’s decision on which URL to choose.

Additionally, Google’s documentation mentions that external links pointing to the wrong page can also affect the choice of the canonical URL. This highlights the importance of checking for any external links that might be directing users to the incorrect page, which could further complicate the issue.

The key takeaway is that if the usual methods of specifying the canonical URL are not yielding results, it may be due to external links, unintended internal linking, or forgotten redirects that are causing Google to select the incorrect URL. John Mueller also suggested that increasing the number of internal links to the preferred URL may help guide Google in making the right choice.