Canonical URLs — One Page, One Address

Leafline's snake plant page can be reached at more addresses than Asha realised:

To a search engine these can look like four pages with identical content, each collecting its own share of links and attention.

The rule

One content, one address; point every copy to it.

Duplicate URLs appear naturally: tracking parameters, sorting and filter options, www versus no www, http versus https, a product listed in two categories. Search engines try to group duplicates and pick one URL to show, called the canonical. You tell them which one you prefer with a tag in the page's <head>:

Every variant carries this same tag, and so does the preferred page itself (a self-referencing canonical), so there is no doubt.

Why it matters:

• Signals combine. Links to different variants count toward one URL instead of being split four ways.
• The right address appears in results, not a copy with ?sort=price on the end.
• Less crawling is wasted on copies.

Two facts to keep straight:

1. The canonical tag is a strong hint, not a command. If other signals disagree, for example your internal links all point at a different variant, the engine may choose differently. Make everything agree: the tag, internal links and the sitemap.
2. Canonical is for duplicates and near-duplicates. Pointing a page at a URL with different content, such as the monstera page at the snake plant page, is a misuse, and engines often ignore it.

For site-wide duplicates such as www or http, add permanent redirects too, so people and crawlers land on the right version.

The shortcut

For every page, ask: "Which URL would I print on a flyer?" That clean address is the canonical, and everything else points to it.

The trap: a perfect canonical tag while menus, breadcrumbs and the sitemap still point at a variant. Mixed signals turn a strong hint into a weak one.

Drills

Answer fast — trust the rule.

Remember

• One content, one address: every copy points to the canonical.
• Shortcut: the URL you would print on a flyer is the canonical.
• The trap: canonicals between different pages, or internal links that contradict the tag.