5 Common Mistakes Webmasters do with rel=canonical!

Apr 9, 2013 | 2,338 views | by Navneet Kaushal
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Google recommends the use of a link with the attribute rel=canonical to indicate your preferred URL. It gives a strong hint to several search engines including Google, Bing, and Yahoo! about your preferred version to index among duplicate pages on the web

The rel=canonical link specifies the URL you would like to be displayed in search results and also consolidates the indexing properties from the duplicates, such as the inbound links. In some cases, especially when there's a misconfiguration, rel-canonical can be a bit tricky. So, Google has shared best practices for using rel=canonical in its Google Webmaster Central Blog.

Image 11 5 Common Mistakes Webmasters do with rel=canonical!

  1. Present a large portion of the duplicate page's content on the canonical version. To check this, place the duplicate side-by-side with the canonical and see if a large percentage of the words of the duplicate page are appearing on the canonical page. In case the pages are just topically similar but not close in terms of exact words, the canonical might be disregarded by search engines.
  2. Make sure that you rel=canonical target exists and is not a soft 404 or an error.
  3. The rel-canonical target should not contain a noindex robots meta tag.
  4. The rel=canonical link should either be included in the <head> of the page or in the HTTP header.
  5. Instead of duplicate URL, prefer rel=canonical URL to be displayed in search results.
  6. There should not be more than one rel=canonical for a page. In case multiple rel=canonicals are specified, all will be ignored.

Google Webmaster Central blog also shared some of the common mistakes we do with rel=canonical. Let's take a look at them:

Mistake 1:

Placing rel=canonical on the first page of a paginated series

In case an article is spanning several pages, specifying a rel=canonical from page 2 or any later page to page 1 is not the correct usage because these are not the duplicate pages. This will result in non-indexing of content on pages 2 and beyond.

Image 2 5 Common Mistakes Webmasters do with rel=canonical!

In the case of paginated content, Google recommends using rel="prev" and rel="next" pagination markup or rel=canonical from component pages to a single-page version of the article.

Image 3 5 Common Mistakes Webmasters do with rel=canonical!
rel=canonical from component pages to view-all page

Image 4 5 Common Mistakes Webmasters do with rel=canonical!
In case the view-all page doesn’t have a designated rel=canonical, the paginated content can use rel=”prev” and rel=”next” markup.

Mistake 2:

Mistakenly writing Absolute URLs as relative URLs

The <link> tag accepts relative as well as absolute URLs. The relative URL includes a path "relative" to the current page. For example, “images/cupcake.png” means “from the current directory goes to the “images” subdirectory, then to cupcake.png.” Absolute URL specifies the full path – including scheme like http://.

Image 5 5 Common Mistakes Webmasters do with rel=canonical!

Specifying <link rel=canonical href=“example.com/cupcake.html” /> implies that desired canonical URL is http://example.com/example.com/cupcake.html , which is certainly not what was intended. In such cases, algorithms may ignore the specified rel=canonical and the desired results will not be achieved with this rel=canonical.

Mistake 3: 

Unintended or multiple declarations of rel=canonical

In most of the cases webmasters copy a page template without changing the target of the rel=canonical. In such cases, the pages of site owner will specify a rel=canonical to the template author's site. Therefore, while using a template, make sure you didn't copy the rel=canonical specification.

Image 6 5 Common Mistakes Webmasters do with rel=canonical!
If you use a template, ensure that you did not copy rel-canonical specification by mistake.

When pages include multiple rel=canonical links to different URLs, the benefit intend to derive will be lost. The SEO plugins often insert a default rel=canonical link, even unknown to the webmaster who has installed the plugin. In such case, Google is most likely to ignore all the rel=canonical hints. 

Double checking the source code of the page will help in correcting the issue. Check the entire <head> section because rel=canonical links might be spread apart.

Image 7 5 Common Mistakes Webmasters do with rel=canonical!
Look at the source code of the page to check the behavior of the plugin.

Mistake 4: 

Landing page or category specifies rel=canonical to a featured article

Let's take an example to explain this better. Suppose you run a site about desserts and the site has useful category pages like "gelato" and "pastry". A unique article is featured each day on the category pages. For instance, the pastry landing page might feature "red velvet cupcakes". In case you add a rel=canonical from the category page to the featured individual article, because the "pastry" category page has almost the similar content as "red velvet cupcake" page, the pastry category page will not appear in search results. The reason behind is, rel=canonical signaled that you prefer search engines display the canonical URL instead of the duplicate. If you want users to find both; featured article and category page, either have a self-referential rel=canonical on the category or nothing at all.

The thing to remember is that canonical designation implies a preferred display URL. So, avoid adding a rel=canonical from landing page or category to the featured article.

Image 8 5 Common Mistakes Webmasters do with rel=canonical!

Mistake 5

rel=canonical in the <body>

Always keep in mind that rel=canonical link should always appear in the <head> of an HTML document. To avoid HTML parsing issues, include rel=canonical as early as possible in the <head>. If Google disregards the rel=canonical designation in the <body>.

The mistake can be easily corrected by double-checking that rel=canonical links are present in the <head> of the page.

Image 9 5 Common Mistakes Webmasters do with rel=canonical!

At the end:

While summing up, Google Webmaster blog shared tips to create valuable rel=canonical designations:

  • The rel=canonical is only specified once in the <head> of the page.
  • Most of the main text content of duplication page should also appear in the canonical page.
  • Avoid specifying rel=canonical from category pages or landing pages to featured article. Because search results will consider featured article as the preferred URL this way.
  • rel=canonical should point to an existent URL with good content and not to a 404 or soft 404.
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Navneet Kaushal

Navneet Kaushal is the founder and CEO of PageTraffic, an SEO Agency in India with offices in Chicago, Mumbai and London. A leading search strategist, Navneet helps clients maintain an edge in search engines and the online media. Navneet's expertise has established PageTraffic as one of the most awarded and successful search marketing agencies.
4.thumbnail 5 Common Mistakes Webmasters do with rel=canonical!
4.thumbnail 5 Common Mistakes Webmasters do with rel=canonical!