# Canonical links

Canonical HTML: /atlas/canonical-links
Atlas version: atlas-2026-07-28-v1
Category: Crawler and indexing directives

## Definition

A canonical link identifies the preferred representative among duplicate or near-duplicate URLs.

## How it works

Search systems combine the declared canonical with redirects, internal links, sitemap entries, content similarity, and other signals before selecting a representative.

## How to validate it

Make redirects, internal links, sitemap URLs, and canonical declarations agree, then verify that duplicate variants remain fetchable but are not promoted as primary.

## Common failure

Canonical is a hint rather than an unconditional command; conflicting signals can cause a crawler to choose a different URL.

## Related topics

- [URL normalization](/atlas/url-normalization)
- [Duplicate content](/atlas/duplicate-content)