Canonical tags assist search engines in recognizing which version of a page’s content they prefer. This is particularly important given that search engines may crawl variations based on parameters, upper/lower case, etc.
Large-scale website duplication can create several SEO challenges, but canonical tags can help rectify them and consolidate PageRank and other signals into one version of each page.
1. Duplicate Content
Duplicate content can harm search engines, yet it often occurs naturally for various reasons. Duplicated text may appear multiple times across a single website or different domains.
Canonical tags are one of the easiest ways to help search engines understand which version of your website should rank higher, effectively telling search engines which page best encapsulates what topic. For example, if an FAQ and product pages contain similar content and you use canonical tags to ensure that only the page with the most useful and pertinent info gets priority ranking.
Canonical tags can also help eliminate duplicate pages on your website; for instance, if two identical blog posts with different titles are available, they can use canonicals to point to the most valuable version, ensuring all link authority and other signals point directly towards it.
One common way duplicate content occurs on websites is when there is an elaborate taxonomy, with multiple categories or tags, on a website. Unfortunately, search engines often struggle to know which taxonomy should be authoritative; to prevent confusion, it may be beneficial to canonicalize all taxonomy pages to the original version of an article.
Remember that unintentionally deleting pages without redirecting them first can create confusion for search engines and lower your rankings, especially if those deleted pages had backlinks or signals that could help them rank.
2. Duplicate URLs
Canonical URLs tell search engines which page version should be considered the authoritative version, enabling backlinks and authority to focus on a single version rather than being spread across various versions of that page. Canonicalization can be especially helpful for websites using content management systems (CMSs) that permit the same content, such as taxonomies or tags, to be accessed from different URLs for various reasons.
An osteopath publishes an educational piece about the most frequent causes of back pain on both their website and that of another nearby clinic with whom they share an agreement, thus publishing the same article twice and leading to potential confusion as to which version of it will rank highest and creating duplicate content issues.
This issue indicates whether or not your CMS is creating canonical tags when there are duplicate pages on your site. To rectify it, redirect any pages using canonical links back to their most relevant place on the website.
Care should be taken not to set canonicals that redirect, as this sends mixed signals to Google and defeats the purpose of canonical tags. For instance, canonicalizing an FAQ page to the product/page would send conflicting signals; Google would interpret this as the same page and disregard its ranking power. Likewise, don’t set canonicals pointing to nonexistent pages, as this will confuse Google and harm your rankings; these must be replaced with working links.
3. Duplicate Meta Descriptions
Meta descriptions allow you to inform search engines what the page is about and increase click-through rates; however, duplicate descriptions across pages can undermine SEO since search engines need help prioritizing one version over the other.
Duplicate meta descriptions may occur due to several reasons, including having similar tags applied across multiple URLs (resulting in them all being indexed), using templates for your descriptions (like “product descriptions,” for instance), or updating title tags from one page to the next but neglect to update descriptions accordingly. It is wise to add self-referencing canonicals for these descriptions to prevent a duplicate content penalty – our Yoast SEO plugin offers this service automatically!
This report shows which pages on your site contain duplicate meta descriptions, and it is wise to remove them to enhance user experience while using only descriptive tags that best suit each page.
This issue indicates that your duplicate content has been assigned a canonical URL, but Google has assessed and indexed another. While not a serious issue, this can create confusion for search engines; to address it, you can submit a new sitemap or use 301 redirects and rel=”canonical” annotations on affected pages to resolve this confusion and increase site rankings.
4. Duplicate Title Tags
Duplicate title tags can be an issue on websites with dynamic or responsive web designs, especially if they utilize search engine results to highlight specific pages with specific content. Title tags distinguish specific content pages in search engine results. They should be unique for every page on a website, preventing duplicate title tags from competing against each other and potentially harming SEO rankings.
Index Status reports in Rank Math’s SEO Tools reveal that Google has discovered multiple URLs with identical content that cannot determine which version should be canonical. This could happen due to structural issues on your site (e.g., duplicate content in sitemap), dynamic website templates that generate multiple URLs with different parameters (e.g.?page=1 or?page=2), or simply duplicated pages within responsive templates that generate different versions with various parameters (e.g.?page=1 or?page=2) or due to structural issues on your site or even structural issues on your sitemap!
This could happen due to various reasons – structural issues on your site (e.g., duplicate content in sitemap) or from dynamic website templates creating multiple versions with identical or very similar pages, which could confuse as Google cannot decide on one version as to its original/canonical version(s) being generated simultaneously for whatever reasons (e.g., duplicate content in sitemap), dynamic or responsive website templates creating various versions that generate URLs using different parameters (e.g.?page=1 or?page=2) being generated as different URLs due to dynamic/responsive website templates creating multiple copies using parameters (e.g.?page=1, or due to using dynamic or responsive website templates that generate many different variations with parameters (e.g.?page=1, or simply due to many page numbers being generated.).
In these instances, it’s hard for search engines to pick them all as it assumes one version is being chosen). This issue or another cause related issue on site or use. It is causing multiple URLs). This might create many pages, one or maybe?page=2, etc).
Canonical tags are pieces of HTML code used to inform search engines which version of a website they should prefer when indexing pages, thus helping reduce duplicate content and rank higher in search results.
Canonical tags can help resolve many types of duplicate content problems when used appropriately; however, when misused, they may lead to penalties due to duplicate content issues.
Canonicalization is an integral component of technical SEO strategy, so it’s vital that you fully comprehend how they operate to use them effectively. Canonicalization helps unify duplicate content versions while ensuring only relevant pages appear in search engine results and improving overall site structure and SEO. Utilizing proper canonical tags and SEO practices may save time and money by eliminating unnecessary development costs.
5. Duplicate Hreflang
If your website caters to multiple languages and countries, use the hreflang attribute to communicate which URLs should be prioritized for search engines in each target market. This helps ensure search engines deliver relevant content to users quickly, improving user experience and increasing conversions. However, be mindful not to mix up hreflang and canonical tags; doing so could cause search engines to misread content duplicate issues as duplicated copies appear elsewhere on your site.
Canonical tags must always point to the canonical version of a page, while hreflang tags should only be used if canonicalization is necessary. Adding an unnecessary hreflang tag could cause search engines to discount it altogether and instead consider the canonical page as original content, potentially harming rankings by penalizing duplicate content sites.
Error code 303 indicates an imbalance of canonical and non-canonical Hreflang tags on your site, creating confusion over which version is the official canonical one and prompting search engines to index pages incorrectly for a region or language.
To correct this issue, review all affected pages and modify their hreflang annotations so they only contain canonical hreflang tags. Any pages containing canonical tags that do not correspond with their HTML language identifier should also have these removed. Finally, ensure all of the pages listed in your hreflang annotations are hosted on one domain or subdomain; this will help prevent a situation where one of your canonical pages ends up on an entirely separate domain or subdomain from your web site, as this could create issues when one or more canonical pages are being served differently from where your web site normally operates.