Duplicates are pages within one site serving the same content at different addresses. Yandex is precise about the boundary: pages on regional subdomains with identical content are not duplicates.
Three costs
- The page you wanted may vanish because the robot chose a different one from the group. Sometimes the pages are not grouped at all, and then they compete with each other — which is worse.
- The indexed address can change, which quietly breaks reporting in analytics.
- Crawling takes longer, so important pages reach the search database more slowly, and the site carries additional robot load.
Finding them
Searchable pages → Excluded pages, filtered by the status Deleted: Duplicate; in the downloadable archive they carry the status DUPLICATE. Duplicates caused by GET parameters also raise a notice on the Troubleshooting page. Note that an AMP page counts as a duplicate of its normal version.
The four patterns and their correct fixes
- Same content at different URLs. A 301 redirect, a canonical declaration, or
Disallow/noindex. Choose which page survives on the basis of what helps visitors — for a set of similar products, keeping the catalogue page lets the visitor see the alternatives. For HTML versus AMP, Yandex recommends keeping the HTML page. - Home page duplicated at
/index.phpand similar. Redirect or canonical — but redirect toward the home page. Yandex points out the trap: redirecting/to/index.phpmeans the content of/index.phpis shown at/, which is the opposite of what was intended. - Trailing slash variants. Use a 301, not canonical — Yandex says canonical may be ignored here. Pick the direction based on which form is already indexed, so you are not forcing a re-index for nothing. On the home page alone, no configuration is needed:
example.comandexample.com/are recognised as the same page. - GET parameters.
Clean-param, or the GET parameter settings in the console.
Where duplicates come from
Two sources, and only one is a defect. Natural duplication — a product listed under several categories — and CMS artefacts: printer-friendly versions, session identifiers, tracking tags, filter combinations. The second group is the one that grows without limit.
Comment nous l'appliquons
On catalogue sites the duplicate list is nearly always one template decision multiplied by thousands of URLs, so we fix the pattern rather than the pages. The trap worth repeating is the home page redirect direction — we have inherited more than one site where /index.php was the indexed home page because the redirect pointed the wrong way, and every backlink in the world was arriving at a redirect.
Services associés