Keyword cannibalisation (or cannibalization) happens when two or more pages on your site target the same search query with the same intent, so they compete against each other instead of against your rivals. It is a common on-page SEO problem on blogs that have published for years without a content plan.
Why it hurts
- Google may rotate which page it shows, so neither builds stable rankings.
- Backlinks and internal links are split between pages.
- The weaker page may outrank the one you want to convert.
- Crawl time and editorial effort are wasted on duplicates.
When it is not cannibalisation
Two pages ranking for the same keyword is not automatically a problem. If Google shows both in the top results, or they serve different intents (a guide and a product page), leave them alone. Cannibalisation is a problem when performance suffers.
How to find cannibalisation
- Search Console: in the Performance report, filter by a query and click the Pages tab. Several URLs with impressions for one query, especially swapping over time, is a red flag.
- Site search: search
site:yourdomain.com "keyword"to see every page Google associates with it. - Rank tracking tools: many flag when the ranking URL changes for a keyword.
- Content inventory: list titles and primary keywords in a spreadsheet and look for overlaps.
How to fix it
Merge and redirect
The most common fix. Combine the best parts of both pages into the stronger URL, then 301 redirect the weaker one. The merged page usually ranks better than either did alone.
Re-target one page
If both pages have value, change one to focus on a different angle or a more specific long-tail keyword, and update its title and headings.
Canonicalise
If both pages must stay live for users (for example near-identical product variants), point one at the other with a canonical tag.
Fix internal links
Make sure internal links with the target keyword point only to the page you want to rank.
Noindex or delete
Thin, outdated pages with no links or traffic can be removed or noindexed.
How to prevent it
- Keep a keyword map: one primary keyword group per URL.
- Check the map before writing anything new.
- Update existing articles instead of writing fresh ones on the same topic.
- Group keywords by shared intent during keyword research.
Frequently asked questions
Can category pages cannibalise blog posts?
Yes, if both target the same transactional term. Give blog posts informational angles.
How quickly does merging work?
Usually within a few weeks of Google recrawling both URLs.
Related terms
See duplicate content, content decay and the SEO encyclopedia.
Mr. SEO
Mr. SEO is the webmaster at SEO TT - SEO tips and tricks, a publication about all things SEO related.