Keyword cannibalisation

Keyword cannibalisation happens when several pages on the same website compete with each other for the same keyword and the same search intent. Instead of one strong page that clearly gives the best answer, you have two or three that say roughly the same thing. Search engines then have to choose, and that choice doesn't always turn out the way you would like.

It isn't a penalty from Google, more a form of confusion. Google says it is normal for several pages from a site to appear for related search terms. The problem only starts when pages genuinely overlap and neither of them is convincing as a result.

How do you spot keyword cannibalisation?

Some typical signs:

• In Google Search Console you see several URLs from your site taking turns getting impressions for a single search.
• The ranking for an important keyword fluctuates sharply, even though you haven't changed anything.
• Google shows a blog post where you actually want your service page to appear.
• You have several pages with almost the same title, such as "Window replacement" and "New windows fitted".

Note: not every overlap is cannibalisation. A page on "replacing windows" and one on "cost of new windows" can exist side by side if they answer different questions.

An example from Dublin

A joiner in Dublin has written five blog posts about wooden windows over the past few years, each from a slightly different angle, and also has a service page. Search Console shows that for "wooden windows Dublin", three pages alternate in the results, none of them ranking high. By bringing the best content from the blog posts together on the service page, redirecting two posts with a 301 redirect and rewriting the rest around specific questions, such as maintenance or insulation value, each page gets its own role. Visitors also find the answer they are looking for faster, instead of having to choose between five similar posts.

How to fix it

1. Map the overlap: which pages target which search terms and which search intent?
2. Choose one main page per intent: usually the page with the best content, the most links or the highest conversion value.
3. Merge or reposition: combine overlapping content, or give a page a clearly different focus.
4. Redirect: point redundant URLs to the main page.
5. Update your internal links: make your anchor texts for the main keyword point to the chosen page.

A canonical tag can help with near-identical pages that both need to stay, but it isn't a solution for pages that are actually redundant.

Why it matters for AI search too

When AI systems such as Google AI Overviews or Perplexity look for a source, they choose a page that answers the question clearly and completely. If your expertise is spread across three half-finished pages, there is probably less chance that any one of them comes out as the best answer. One strong, well-structured page per topic makes your site clearer, for search engines and for language models alike.

Cannibalisation often creeps in unnoticed as your site grows. A visibility audit of your website maps overlapping pages and shows which page is best chosen as the main page.