What is keyword cannibalisation? How can it be eliminated?

What is keyword cannibalisation? How can it be eliminated?

Keyword cannibalisation can be problematic when ranking a site. It occurs when at least two subpages of one website are based on the same keywords. Then, it is difficult for algorithms to subordinate a specific subpage to a given phrase. How to detect and counteract cannibalisation?

What is keyword cannibalisation?

Keyword cannibalisation is when Google's search engine displays two sub-pages belonging to the same domain for one phrase. When ranking a website, it is important to optimise the site to avoid this phenomenon. Cannibalisation generally has a negative impact on conversions, as it makes it more difficult for the user to find the desired information using the search engine.

We know that Google, Bing and other search engines, which have developed very sophisticated content recognition mechanisms, are sensitive to the use of certain phrases. If we want our blog article to appear high in the search results for internet users who are looking for information about green tea from Nigeria, we will try to include, for example, the phrase "Nigeria green tea" and its variations in the article headings and paragraph content. If the other parameters of our page are properly configured, we stand a good chance of generating a lot of interest in our article among Internet users who are looking for information specifically about green tea from Nigeria. Creating content using keywords is preceded by a thorough analysis of their popularity. Through various tools, such as Ahrefs, positioners verify the competitiveness of phrases, how often they are searched for. The analysis of these and other parameters makes it possible to find relevant phrases that are searched for by internet users and at the same time are related to the topic of the website, blog or online shop.


These are the absolute basics of SEO for web text. If the various sub-pages of a site are also optimised with exactly the same phrases, Google's algorithms will be confused. There will be content cannibalisation, i.e. repetition of the same phrases in several sub-pages of one website. Optimising multiple pages of a website for the same keyword has a negative effect on the position of the site. In such a case, we are no longer competing with other sites for the delivery of a given content, but it is our own pages that are competing with themselves. The algorithm does not know which page to display for a given query, and as a result, all our pages optimised for the same keyword struggle to stand out. Unintentional chaos ensues in the search results - Google does not know which page from our domain to choose to display.

Every action we take on the internet leaves its mark. What we write is read not only by the people we want to reach, but also by algorithms that select content according to queries. The text should therefore be readable by the user, but also by robots searching the internet. We do not have full data on how Google's algorithms work, but we still know enough to determine whether a text will be well received or whether we will attribute the error of cannibalising keywords to it. Many tips can be found in Google's tips for webmasters.

If you notice in your site data analysis tools that different sub-pages of the site are using the same ranking keywords, then you should act more quickly. You can also see this when you observe how internal linking has been carried out between parts of the site, and especially when you see two identical H1 headings within a single domain - this is also when you diagnose keyword cannibalization

Symptoms of keyword cannibalisation

When two different URLs within the same domain are optimised for the same phrase, there is a high probability that keyword cannibalisation will occur. In such a situation, it is difficult for Google's robots to determine exactly which page should be displayed to users for a generated query. Site owners without optimisation knowledge often believe that such a phenomenon positively affects organic traffic. More often than not, however, content cannibalisation is a huge problem, through which conversion drops significantly and rejection rates increase.

With several sub-pages from a single domain displayed in a search engine for a single keyword, the individual URLs begin to compete with each other. The result is a lower CTR, as users start to open different sub-pages instead of heading to one - the one that fits best. Such a phenomenon is called content cannibalisation, as the results start to 'eat each other up', subsequently dividing conversion, CTR and traffic between different URLs. If, for example, an online shop sells furniture, a subpage with desks should not be optimised for the phrase "furniture shop" but for "office desks", "modern desks", etc. When the website is correctly optimised, possible problems with keyword cannibalisation may arise mainly during the development of the website. A frequent reason for the display of several URLs of one domain in a search engine is blog articles that consist of the same or twin phrases as product/service and category descriptions.

Is keyword cannibalisation always a bad thing?

Although cannibalisation of key phrases generally leads to negative consequences, its effects are not always so clear-cut. For some websites, the display of several URLs under a single key phrase is either neutral or positive. Such domains are an extreme, so it is definitely better to simply avoid cannibalisation. The only exception to this is where the domain owner is confident that the cannibalisation does not negatively affect the conversion and traffic of the site.

The risks of keyword cannibalisation

John Mueller (Senior Webmaster Trends Analyst at Google) was asked about SEO cannibalisation on Twitter. In response, he stated that in a search engine, several pages from one domain start to compete with each other. Therefore, it is better to have one stronger URL than to have several weaker ones.

Low relevance of pages in search engine

Google's algorithm functions to display users the best possible answers to the queries sent. The search engine often presents information in the form of dedicated featured snippet boxes, while at the same time trying to 'pull' from each valuable domain a single URL tailored to a specific topic. When a site has two (or more!) sub-pages optimised for exactly the same keyword phrases, the algorithm will struggle to determine which one is better suited to the user's intent.

Decrease in conversions and increase in rejection rates

The consequence of cannibalising key phrases can be that the wrong URLs are displayed to the user. Opening the link will then not lead to a conversion and, in an extreme situation, will increase the rejection rate. Both pages appearing in a Google search will only be moderately relevant and not perfectly relevant to the user's needs.

Poor effectiveness of SEO strategies

Many times content cannibalisation takes place on domains that rank very high for a particular key phrase. In theory, these should generate traffic and record a high CTR. However, users have to choose between one of two URLs. When this happens, the CTR starts to drop, as viewers 'split' between the two sub-pages instead of opening just one of them. According to a study by Moz, the CTR affects a website's position in Google search. Therefore, SEO cannibalisation reduces the effectiveness of SEO activities

Gaining a deep understanding the problems that customers face is how you build products that provide value and grow. It all starts with a conversation. You have to let go of your assumptions so you can listen with an open mind and understand what’s actually important to them. That way you can build something that makes their life better. Something they actually want to buy.

What to do in the event of keyword cannibalisation?

If you found out about cannibalisation too late and found that it needs to be worked on, then consider a few things. Eliminating cannibalisation is not easy, and a great deal of time needs to be spent on it. Eliminating cannibalisation can take a very long time and be extremely complicated. It is not uncommon for it to take a few months, but in some cases a few weeks of work may be enough. How quickly the problem can be dealt with depends on the skills of the specialist in charge, but also on the number of pages with the same keyword and the multiplicity of cannibalised phrases.

After a thorough analysis of all cases of SEO cannibalisation, several decisions should be made. The first should be which sub-page should be ranked for the recurring phrase. Only one of these should be chosen; the choice depends on which subpage is more valuable to you. Once you have decided whether it should be, for example, an offer subpage, a guide subpage or a blog subpage, also look at other subpages containing the same keyword. Match them with other phrases you care about. Then, optimise these sub-pages for your chosen keywords. It is a good idea to use long-tail keyword phrases and phrases related to local ranking. SEO experts will perfectly select the right keywords and change the content of the subpage so that it is no longer identified with the previous phrases. If you do not want to wait for the SEO cannibalisation to disappear, you can also delete the subpage in question, but then you will lose very important, sometimes crucial content.

Site Diversity Update and the impact on SEO cannibalisation

In June 2019, Google's search engine received a Site Diversity update. This is a significant change in terms of keyword cannibalisation. With it, a search listing can consist of up to two results leading to a single website. It is relatively rare for a search engine to display as many as three sub-pages. After the implementation of the update, domains that were previously ranked lower by huge competition have gained a higher position. Today, even the largest domains with huge authority are not able to occupy the entire SERP listings. Previously - before the Site Diversity Update - a deliberate SEO cannibalisation of content was used for some sites, only to flood the entire TOP 10 with links to one domain. Today, this practice has completely lost its meaning. Currently, from an SEO point of view, the best solution is to assign individual key phrases to a single URL.

Google.com. Search results after implementation of Site Diversity Update (left side) and before the update (right side).

As a result of the Site Diversity Update, the creation of subdomains with similar content has also lost its meaning. It is almost impossible for one site to occupy the entire Google search listing. If a subdomain has similar content to the main domain, they will be treated as a "common whole" by the algorithm. Only subdomains with completely different content are still understood as a separate site. Therefore, using cannibalisation to increase traffic from June 2019 is practically unfeasible. Domains with multiple pages optimised for the exact same key phrase under the Site Diversity Update may have seen a significant drop in visibility. Some URLs began to completely fail to display in the search engine or appeared in a significantly lower position.

How do you check if keyword cannibalisation is occurring on a page?

It should be avoided that several pages are optimised for the same keywords. This can be a difficult task, above all for owners of sites with strictly defined topics. However, measures to avoid cannibalisation should be approached with care. Google's algorithms aim to match the best matching sub-page for each phrase. The effect of SEO cannibalisation will be the so-called exchange of sub-pages in the search results under the keywords in question. This is why it is important to check whether cannibalisation has occurred on a particular site. This can be verified in a number of ways with a variety of tools. These include, for example, Senuto, which has a "cannibalisation" tab. This makes it possible to check whether specific phrases have been SEO cannibalised and which sub-pages are optimised for them.

You can also detect keyword phrase cannibalisation via Google Search Console (by checking which subpages the keywords are found on). Ahrefs also displays keyword cannibalisation, just go into the organic positioning statistics and check the keywords appearing on a given website. If they appear under several subpages, then we have keyword phrase cannibalisation. These are just some of the tools that will allow you to check content cannibalisation. However, they are the most commonly used, as they allow you to observe a variety of indicators regarding the optimisation of your website for organic positioning.

Specialist analytics tools should be used to quickly search for cannibalisation. The software will scan the entire domain to verify individual URLs for content. SEMrush or Senuto are most commonly used for this purpose. Both tools are paid, but they are simple to use and the results will show any keyword cannibalisation within the domain.

How do you eliminate keyword cannibalisation?

Above all, website owners should avoid keyword cannibalisation through prevention and a proper optimisation plan. To this end, it is worth preparing a comprehensive keyword phrase selection. This is a document (usually created in a spreadsheet) where key phrases are assigned to each URL. These cannot then be used to optimise any other pages than those indicated in the selection.

However, if SEO content cannibalisation does occur, all steps must be taken to remove it from the site. Several optimisation techniques are used to do this. These ensure that all key phrases are assigned to the most relevant subpages.

Updating content and page descriptions - the basic element is proper content optimisation. Each sub-page must have unique meta data (title and description) with keywords. A phrase assigned to one subpage should not be used when optimising subsequent URLs. The same principle applies to content creation.

Internal linking - sub-pages should be linked internally, for example by creating links from the blog to categories or products. Anchor texts in links are a 'clue' for Google's robots, which tells them exactly what is hidden under a particular page. If SEO cannibalisation still occurs despite updated content and the use of unique content, it is worth thinking about additional internal linking.

Site architecture - sometimes a category may be displayed under a typical product phrase (or vice versa). It is therefore important to create an optimised architecture within which it becomes easier for users and Google robots to navigate the site. Are the breadcrumbs created correctly? Or are subcategories missing or the main categories incorrectly named?

Tag canonical - identical or twinned versions of subpages should be tagged with a canonical tag. The URL will then not be displayed in Google search, which prevents possible cannibalisation of content and duplicate content. Such a tag is used, for example, for consecutive category sub-pages where a list of products is displayed.

How to prevent cannibalisation?

The best action is to prevent keyword cannibalisation from the very beginning of the site. This will ensure that you do not have to put a lot of work into fixing this aspect. To do this, the best thing to do is (once you have chosen your keywords), list the sub-pages and assign them specific phrases for which you want your website to be positioned. This will ensure that there is no cannibalisation of content on your website. At the same time, it is worth verifying from time to time whether SEO cannibalisation has occurred. Ideally, this should be done on a monthly basis using both free and paid tools for SEO specialists. The sooner you spot it, the easier it will be to eliminate the problem.


Keyword cannibalisation can be a serious threat to your site's position in Google search results. It is best to prevent such situations as they are not good for your site's visibility. However, if the problem has arisen, you need to perform a thorough analysis and then take appropriate corrective action. With these, it is possible to fix the optimisation of the website. You can easily test the lack of action once cannibalisation has been detected. Observe how your website's position in Google's results gradually drops and you will see that cannibalisation of key phrases is not something trivial. If you don't want to test this aspect yourself, preferring to act right away or fix the effects of cannibalisation, then get in touch with specialists. The positioners at Semcore will help you with this problem and will make sure that your website ranks well in the search results for other issues that affect it as well.

It is worth knowing that keyword cannibalisation is a serious problem for many sites. This phenomenon can have a negative impact on conversion rates, further hampering SEO efforts. Although in some cases keyword cannibalisation takes on a neutral character and has little significance in terms of traffic acquisition, it is best to reduce it for security reasons. It is worth taking this fact into account not only when optimising the website, but also when creating new pages.

FAQ on keyword cannibalisation

What is keyword cannibalisation?

Keyword cannibalisation is when two (or more) URLs belonging to the same domain are displayed in search results for a user's query. The search engine then struggles to determine which answer is a better match to the internet user's intent.

Does keyword cannibalisation affect a website's SEO?

Keyword cannibalisation can hinder the SEO of a website due to the fact that the search engine algorithm will not 'know' which URL is the best answer to a user's query. Moreover, the phenomenon of keyword cannibalisation creates an internal competition between sub-pages for a high position in Google.