What is keyword cannibalisation?
Keyword cannibalisation occurs when multiple pages on your website rank for the same keyword and the same intention. When this happens, you are effectively splitting the SEO value of each page, therefore lowering the search rank and potentially losing out on traffic and conversions.
Intent and Keyword Cannibalisation
Keyword cannibalisation only occurs when multiple pages are targeting both the same keyword and the same intent. However, it doesn’t occur when two pages target the same keyword but a different intent.
For example, if a user is looking for the best moisturiser for their dry skin, they could be doing some research to find the best product OR they could be ready to purchase. If you had two pages ranking for the same keyword (e.g. Glo-Skin Moisturiser), one could be a review (targeting the research stage), and one could be a product page (targeting the ready-to-buy stage).
If a keyword happened to be relevant to both intents, and both pages appeared in search at the same time, this wouldn’t be cannibalisation. The content would be portrayed differently based on the next actions the user is likely to take.
Why is keyword cannibalisation bad?
On the surface, the results of keyword cannibalisation can seem positive. For example, if you have one page that ranks in multiple positions in the SERPs (search engine results pages), you’re taking up more space and reducing competitor visibility. Right?
Well, yes, but that’s not the only consideration here.
Keyword cannibalisation isn’t inherently bad. Like many elements of SEO, whether you worry about it depends on the situation. If multiple pages are ranking well for the same keyword, then it may not be a problem. However, if multiple pages are ranking low in the SERPs for the same keyword, then cannibalisation is likely an issue.
Lots of factors affect how you rank on Google, including content quality, relevance to the search, page authority, and the number of backlinks. Keyword cannibalisation can dilute these factors and therefore give you a lower ranking than if you were to just have one page.
Let’s look at some examples of the negative affects of keyword cannibalisation.
If you have more than one page ranking for the same keyword, you’re splitting all your ranking metrics by the number of pages. And when your metrics are split, so is your authority.
Click-through-rate (CTR) is a good example. Because CTR is an important metric that Google uses to decide where your page ranks, the higher it is, the better.
Imagine you have two pages ranking for the same keyword. There’s a chance that those two pages are pretty similar (otherwise they would rank for different keywords). So, if someone searches and then clicks through to your content, which page do they select? Imagine 25 click through to Page A, and 25 to Page B.
Now, if the similar content on those two pages was combined onto a single page, instead of having two pages with 25 clicks each, you’d have one page with 50 clicks, and therefore a much higher CTR.
Consider this, too. If your competitor has 40 clicks, they’d likely rank higher than your two separate pages. But they’d rank lower than your single 50-click page.
The same can be said for other influencing factors such as backlinks (links to your site from external websites).
Note: This is a simplification of how ranking factors work, but useful for illustration purposes.
Reduced content quality
Google and other search engines value high-quality, in-depth content. If you spread a certain topic over multiple pages, you may be reducing its quality by including large amounts of duplicate information or creating ‘thin’ content that doesn’t contain much of use or interest. This will reduce your chances of ranking well in search, whereas combining the content could make your topic more useful to the user, and therefore better for your rankings.
Lack of control
Keyword cannibalisation forces Google to pick one of multiple similar pages to show in the SERPs. And the page it picks may not match with the page you think is better. For example, Google may select the page that has the most backlinks, whereas you may prefer it to display a page with fewer backlinks, but which converts better.
Of course, you can’t ‘pick’ which page shows on Google, but you can influence Google to select the preferred page by ensuring your not cannibalising your keywords over multiple pages.
Wasted crawl budget
This one won’t be relevant if you only have a small number of pages. But if you have a large site, or an e-commerce site, it’s very important.
In order to rank your pages, Google – and other search engines – crawl your website. Without crawling, your pages don’t end up on Google.
However, each website is limited to the number of pages Google will automatically crawl within a certain period of time – i.e. it has a crawl budget. If this budget is being used up ranking similar pages, some of your more valuable pages may not end up on Google at all. Which means users can’t find them through search.
How to identify keyword cannibalisation on your website
To use this option, you will need to have already been using it for some time, otherwise there won’t be enough data to analyse. Log in via your Google account and select Search Results from the left menu.
Scroll to below the graph and you’ll see several tabs, including Queries and Pages. Queries gives a list of searches that your website appeared for, and Pages shows you which pages on your site appeared in search.
Click on any query to filter the results and then switch to the Pages tab to discover the pages that showed in search when that particular keyword was entered. How do the results look? If there are multiple pages, then you may have a problem with cannibalisation. You’ll have to assess each page manually to identify any potential issues.
You can also export your results in a spreadsheet, which will show more data such as where each page ranks in the SERPs.
Other free tools to help identify keyword cannibalisation include:
If you’ve got some budget behind you, consider looking at paid tools. Semrush is one of the most popular and provides lots of additional features that will help your overall SEO (though it may be out of budget for smaller organisations – take a look at some alternatives below).
The advantage of paid tools is that they’re quicker. With something like Semrush compared to Search Console, you minimise the manual process.
Other paid tools to help identify keyword cannibalisation include:
Fixing keyword cannibalisation
As mentioned earlier, keyword cannibalisation isn’t always an issue. But if you have multiple pages ranking for the same keyword, and if they’re all ranking poorly, then you should consider these keyword cannibalisation fixes.
Combine pages and redirect
If two pages cover a similar topic without much variety in the content, then it would perhaps be better to combine them into one page. Identify which performs better (how you determine this is up to you – it could be through rankings, click-through-rates or conversion rates, for example).
Identify what makes your primary page better and make sure you retain those elements, then add any relevant content, functionality, or features from the secondary pages. When this is done, you can remove the secondary pages and redirect them to the primary – and now only – page on that topic.
Review keyword targeting
Could one of your pages be adjusted to cover a slightly different topic? For example, if two pages rank for the keyword moisturiser, they might have similar content, but one may talk more about moisturiser for a specific skin type. In that case, you could update the content to target a different keyword such as moisturiser for oily skin.
By doing this, you keep pages, and any authority they’ve received so far, but you target a different search. Make sure this sub-topic, or parallel topic, is valuable – you don’t want to replace poor content with slightly different poor content.
Sometimes it’s necessary to have multiple pages that are similar, and getting rid of one of these pages would be detrimental to your site. In these cases, help Google understand which is your preferred page by using canonical tags.
Canonical tags tell Google which page – of multiple similar pages – to prioritise in search.
Keyword cannibalisation can be a problem when a less relevant but more authoritative page ranks for a certain search term.
This can be seen a lot in e-commerce sites and other websites that make use of a lot of sub categories and child pages.
Looking at our moisturiser example again, you may have a primary page for moisturiser, and child pages for hand cream, foot cream and face cream. If, for some reason, the hand cream page has a higher authority (it could have better content, more backlinks, or better functionality), then it may end up ranking better for the more general moisturiser keyword, when you really want the top-level moisturiser page to rank for that keyword.
In such a situation, you should analyse the top-level page to optimise it more effectively. This could be by adding more internal links, ensuring the user experience is top-notch, or updating the content. Take a look at my website audit guide to get started.
Add NoIndex tags
NoIndex tags tell Google not to crawl a particular page. They should only be used as a last resort if the above improvements aren’t relevant or successful.
With NoIndex, a page remains live on your site, but is removed from search engine rankings. Because of that, you also lose all authority and ranking signals that it may bring to your website as a whole.
Like canonical tags, you will need a basic understanding of HTML to add NoIndex tags, or will have to utilise a developer or WordPress plugin.
Keyword cannibalisation can prevent pages from ranking well in search through diluting positive SEO signals. Though not necessarily a problem when your pages rank well, low-performing pages can be improved by looking for possible cannibalisation. Fix potential issues by creating unique content on each page that both targets different keywords and different user intents.