Canonical tag: telling Google which version of a page is the real one

A canonical tag (<link rel="canonical" href="…">) in a page’s head tells Google which URL is the main version when several URLs show the same or similar content, such as tracking parameters or filtered product lists. Every indexable page should point to itself. Google treats it as a strong hint, so keep internal links, sitemaps and redirects consistent with it.

By Hassan Rawther, Founder, Unlearn Academy · Reviewed 21 October 2026

Four URLs, one page, no rankings

A Kochi store’s category page was reachable at four URLs: with and without “www”, with a trailing slash, and with ?sort= parameters. Search Console picked a different one each month.

The theme had no canonical tags and internal links used mixed URLs.

We set self-referencing canonicals, a single www redirect and consistent internal links. Google settled on one URL, and the page climbed from page 3 to page 1 within two months.

Illustrative example based on a common pattern in Kerala e-commerce accounts. Numbers rounded.

What a canonical tag is

Duplicate URLs split signals like links between versions. The canonical tag points them all to one preferred URL.

Most SEO plugins add a self-referencing canonical automatically. You change it only for true duplicates that must stay live.

<link rel="canonical" href="https://www.yoursite.in/main-page/">

Canonical check

Check one important page for canonical problems.

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Big gaps. Start with the first unticked item; each one is a quick win.

Stuck on one? Join the community and post it for doubt-clearing.

Canonical vs redirect vs noindex

UseWhen
CanonicalSimilar pages must both stay live (filters, print versions)
301 redirectThe old URL should disappear
noindexThe page should stay live but out of Google

How experienced marketers use Canonical URL

  1. 1. Tracking parameters

    ?utm_source= and ?gclid= URLs point their canonical to the clean URL.

  2. 2. E-commerce filters

    Filtered and sorted listings point to the main category.

  3. 3. Syndicated content

    Articles republished elsewhere can point back to your original.

What good looks like

Business typeStarting ruleWhy
Indexable pages100% self-referencingDefault in good SEO plugins.
Canonical chainsNoneCanonical should point to a final URL.
Search Console mismatchInvestigate anyShows Google disagrees.

When the number lies

A hint, not an order
Google may choose a different canonical if signals disagree.
JavaScript-only canonicals
Canonicals added late by scripts may be missed; keep them in the HTML head.

Mistakes to avoid

  • All canonicals pointing to the homepage

    Google ignores your other pages.

  • Canonical to a redirected or noindexed URL

    Mixed signals; Google may ignore it.

  • Using canonical instead of a redirect

    Old pages linger in search.

Related terms

Questions people ask about a canonical tag

What is a canonical tag?

An HTML tag that tells search engines which URL is the main version of a page.

Should every page have a canonical tag?

Yes, every indexable page should have a self-referencing canonical.

Canonical or 301 redirect?

Use a 301 when the old URL should go away; use a canonical when both versions must stay accessible.

How do I check the canonical Google chose?

Use URL Inspection in Search Console: compare user-declared and Google-selected canonical.

Put it into practice

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