Canonicalization is the process of selecting the representative – canonical page/URL –  URL of a piece of content from a set of duplicate pages. Often called deduplication, this process helps Google show only one version of the otherwise duplicate content in its search results. Keyword cannibalization occurs when multiple pages on the same website target the same keyword, unintentionally competing with each other. Instead of boosting rankings, this confuses search engines, making it harder for them to determine which page should rank higher.

If you’re experiencing fluctuating rankings, lower organic traffic, or inconsistent search results, canonical pages or keyword cannibalization or both might be the hidden culprit.

Let’s dive into it.

Canonicalization

Canonicalization refers to the use of a canonical tag (<link rel="canonical" href="...">) to tell search engines which version of a page is the preferred one when multiple pages have similar or duplicate content.

A canonical tag, also known as a canonical link or "rel canonical," is a tag in the source code of a page that indicates to search engines that a master copy of the page exists. Canonical tags are used in SEO to help search engines index the correct URL and avoid duplicate content.

A canonical URL is the URL of a page that Google chose as the most representative from a set of duplicate pages.

Example: If you have:

• example.com/page-a
• example.com/page-a?ref=123
• example.com/page-a?sort=price

You can set the canonical tag on all of them pointing to example.com/page-a.

Reasons for duplicate content

There are many reasons why a site may have duplicate content:

• Region variants: for instance, a piece of content for the USA and the UK, accessible from different URLs, but essentially the same content in the same language.
• Device variants: for example, a page with both a mobile and a desktop version
• Protocol variants: for example, the HTTP and HTTPS versions of a site
• Site functions: for example, the results of sorting and filtering functions of a category page
• Accidental variants: for example, the demo version of the site is accidentally left accessible to crawlers

Some duplicate content on a site is normal and it's not a violation of Google's spam policies. However, having the same content accessible through many different URLs can be a bad user experience. For example, visitors/people might wonder which is the right page, and whether there's a difference between the two. This may make it harder for you to track how your content performs in search results.

Purpose of Canonicalization:

• Prevents duplicate content issues
• Consolidates link equity (ranking power) to the main version
• Helps search engines index the correct URL

How Google indexes and chooses the canonical URL

When Google indexes a page, it determines the primary content (or centerpiece) of each page. 

If Google finds multiple pages that seem to be the same or have very similar primary content, it chooses the page that, based on the factors (or signals) the indexing process collected, is objectively the most complete and useful for search users, and marks this page as canonical.

The canonical page will then be crawled most regularly while the now “duplicate pages” are crawled less frequently. This helps to reduce the crawling load on sites and rank the canonical page better.

There are many factors that play a role in canonicalization: 

• whether the page is served over HTTP or HTTPS, 
• redirects, 
• presence of the URL in a sitemap, 
• rel="canonical" link annotations

You can indicate your preference to Google using these techniques. But, Google may choose a different page as canonical than you do, for various reasons. Simply put, indicating a canonical preference is just a hint to Google, not a rule.

Note that different language versions of a single page are considered duplicates only if the primary content is in the same language. That is, if only the header, footer, and other non-critical text is translated, but the body remains the same, then the pages are considered to be duplicates).  

Google uses the canonical page as the main source to assess and evaluate content and quality. A Google Search result usually points to the canonical page, unless one of the duplicates is explicitly way better suited for a user. For instance, the search result will probably point to the mobile page if the user is on a mobile device, even if the desktop page is the canonical.

Keyword Cannibalization

Many people believe that having multiple pages (duplicate  pages) about the same thing confuses search engines and leads the pages to rank “wrong” and confuse users.

They’re right. Having duplicate pages can lead to unexpected or undesirable rankings. But it doesn’t always mean that something’s wrong or needs fixing. 

On the brighter side, it can occasionally signal an opportunity to consolidate content to improve rankings and organic performance.

What is keyword cannibalization?

Keyword cannibalization in SEO is an issue that happens when multiple pages on a website target the same or similar keywords. This leads to a situation where the site’s pages compete against each other for search engine results or rankings. Like in duplicate pages, cannibalization can confuse search engines about which page to rank, potentially lowering the visibility of all the pages involved. Put simply, this can dilute the website’s ability to rank effectively for targeted keywords.

Keyword Cannibalization example

For example, let’s say we have two pages in BoostSiteSeo.com about technical SEO:

• example.com/technical-seo-guide-2025 
• example.com/technical-seo-practices-2025

If we could get more organic traffic overall by combining the two pages into one, that’s a cannibalization issue. The existence of those two pages is eating away at our organic performance.

Keyword cannibalization isn’t a good thing on the website. But, generally, you only have a real keyword cannibalization issue when multiple pages target the same keyword and hurt a site’s organic performance.

For example, assuming we have two pages targeting the same keyword (technical SEO). One of them, which we’d prefer to rank, isn’t anywhere to be seen, but the other ranks #1. This is textbook keyword cannibalization because one page is seemingly “cannibalizing” the other’s traffic.

Why Addressing Keyword Cannibalization Is Crucial 

Here’s why it's a big deal for SEO:

• Dilutes Page Authority: Instead of having one strong page, you split your authority between several weaker ones.
• Hurts Rankings: Google may rank the wrong page (less relevant or outdated), reducing your click-through rate and conversions.
• Wastes Crawl Budget: Search engines may spend time crawling duplicate pages rather than more important ones.
• Confuses Search Intent: It becomes unclear which page best serves user intent.
• Inefficient Internal Linking: Internal links might be spread across several similar pages, weakening their collective SEO power.

How to Identify Keyword Cannibalization

To find real cannibalization issues, look for pages that (1) target the same keywords and (2) fulfill the same or very similar intent. Otherwise, you may not need to worry because pages often rank for many other keywords. Why?

If the intent is the same, each page is unlikely to be ranking for lots of different long-tail keyword variations. So there’s usually more to gain than lose by consolidating the pages.

1. Do a content audit

Unless your site is huge, cannibalization issues should be relatively easy to spot during a content audit. Use tools like Google Search Console, SEMrush, Ahrefs, or Screaming Frog to find pages ranking for the same keyword.

2. Look at historic rankings

Historic keyword ranking works best when you want to check for keyword cannibalization issues for a specific keyword, such as technical SEO. Find pages that were published different times, rank for similar keyword, but rank differently on the search engine. 

3. Run a site: search

Search: site:yourdomain.com "your keyword" on Google and analyze the results. You’ll see all the pages on your site related to that topic.

For example: site: boostsiteseo.com “technical SEO” You’ll see all the pages on our site related to “technical SEO”.

4. Check for multiple ranking URLs

If Google ranks multiple URLs for a keyword, that can be a sign of a cannibalization issue.

How to fix keyword cannibalization issues

It’s simple, merge content into one comprehensive page.

If you’re confident that you have a keyword cannibalization issue on your hands, merging or consolidating the pages can improve organic performance. This is the one key solution.

That may mean:

• Redirecting an old, outdated page: 301 redirect lower-performing pages to the most authoritative one or to something more relevant that you already have.
• New content. Combining multiple pages into something new.

Keyword cannibalization solutions never recommend

People can try different other solutions to fix cannibalization. But don’t fix keyword cannibalization with the following solution: 

1. Don’t delete the page

Deleting a page is rarely a good solution unless the page has no value for your business or ranks for only the “cannibalizing” keyword. Both of these scenarios are often unlikely, so this is a rare thing to do in the face of cannibalization.

2. Don’t no-index the page

Noindexing causes search engines to drop the page from their index, meaning it won’t rank for anything, making it a terrible way to fix cannibalization. It also highlights why tackling cannibalization at the keyword level is almost always a bad idea.

3. Never canonicalize the page

Remember how we talked about cannibalization above. Never canonicalize a page because of cannibalization. 

Canonicalization is only a viable solution when dealing with multiple pages that are near or exact duplicates, or simply duplicate content or pages. Canonicalization is not a way to fix keyword cannibalization. 

4. Don’t de-optimize the page

De-optimizing a page only makes sense in theory but is fundamentally flawed. Why would you de-optimize a page for just one keyword? Things don’t just work that way. For example, removing all internal links with the cannibalizing keyword as the anchor is likely to affect the page’s rankings for other keywords too. The same is true for removing mentions of the cannibalizing keyword from the page. 

Final thoughts

Canonicalization helps Google show only one version of the otherwise duplicate content in its search results. It’s good for your search rankings, especially when you’re trying to avoid duplicate content and targeting particular keywords. For example, at BoosSiteSEO, our target is anything SEO, we will rank for most pages with SEO, but when two pages have similar urls regarding technical SEO, we’d rather combine them into one to get a big traffic.

Keyword cannibalization isn’t really a thing—at least not in the way most people understand it. Google doesn’t get “confused” by multiple pages about similar things or pages targeting the same keywords. It knows what’s on those pages and ranks them accordingly.

Does that mean Google will always rank the page you want it to rank? Of course not. But that doesn’t mean that it’s “ranking the wrong page” or that drastic action is required to “fix” the problem. 

Many common “solutions” to duplicate pages or keyword cannibalization do more harm than good. Do better and find out first before taking an action.