Keyword cannibalisation happens when several pages on your site answer the same search in much the same way. Instead of one strong page, search engines see several similar ones and have to guess which to show — often ranking none of them as well as a single page would.
It is not a penalty, and two articles on related subjects are not a problem in themselves. It becomes one when the pages have the same intent: a reader searching for it would be equally happy — or equally unsure — with either.
Where it comes from on WordPress sites
- Overlapping categories and tags that list the same articles under different names. See Categories vs tags.
- Several “main” articles for one topic, none clearly the pillar. See Pillar pages.
- Updated versions published as new articles instead of updating the old one (“Best cafés 2023”, “Best cafés 2024”).
- Seasonal clusters that duplicate a broader one: “Christmas in Stockholm” next to “Festive traditions”.
Recognising it
- Two of your pages take turns ranking for the same search, or both sit on page two.
- Your own articles would give a reader the same answer.
- You hesitate over which one to link to.
Three ways to fix it
1. Merge. Combine the pages into one stronger article, keep the best parts of each, and redirect the old URL to the new one. Best when the pages really are about the same thing.
2. Differentiate. Give each page a clearly different angle and intent — a practical planner versus a history, a list versus a review — and make the titles and descriptions say so. See Meta titles and descriptions.
3. Choose a main page and point to it. Keep both, but make one the clear main page: link to it from the other with descriptive anchor text, and link the rest of the cluster to it too.
For archive pages (tags and categories), a fourth option is to keep a duplicate tag for navigation but keep its archive page out of search.
In ClusterIQ
ClusterIQ doesn’t read search rankings, but it shows the structure behind most cannibalisation: overlapping clusters on the Site map, several articles competing to be a cluster’s main page, and articles that don’t link to the chosen pillar. With Pro, Site Intelligence Analysis names overlapping clusters and links to the tool that fixes them. Merging pages and redirects are done in WordPress itself.
Back to the overview: Topic clusters.