iFastHostingWhat is a canonical tag?
A line in the page head that tells search engines which of several similar URLs is the one that should actually be indexed.
A canonical tag is a line in a page's <head> that names which URL should be treated as the definitive version when several URLs show the same or near-identical content. It looks like this:
<link rel="canonical" href="https://yourdomain.com/actual-page/" />It is a hint search engines usually follow, not a rule they are forced to obey. When several URLs point to a chosen canonical, the ranking signals those pages had individually tend to consolidate onto the one named as canonical, rather than being split — and diluted — across duplicates.
Why duplicate URLs happen even when you did not mean to create them
Most sites end up with unintentional duplicates without anyone deliberately creating them:
- The same page reachable at both
https://yourdomain.com/pageandhttps://www.yourdomain.com/page. - A URL that works identically with or without a trailing slash.
- Tracking parameters appended to a shared link —
?utm_source=newsletter— creating a technically different URL for the same content. - A product reachable through more than one category path on an e-commerce site.
A canonical tag on each of these pointing at one chosen version tells search engines these are variants of a single page, not competing content.
How it differs from a redirect
A canonical tag and a 301 redirect can look like they solve the same problem, but they behave differently. A redirect sends the visitor to the new URL — they never actually load the old one. A canonical tag lets the page load normally at its own address and only tells crawlers which version to prefer for indexing; a human visitor never sees any difference. Use a redirect when a URL should stop existing as a destination at all; use a canonical tag when several versions genuinely need to keep working — such as a page reachable through more than one legitimate path — but only one should be indexed.
The simplest and most robust setup is for every indexable page to carry a canonical tag pointing at itself. This costs nothing and prevents an entire category of accidental duplication — an added tracking parameter, for instance — from ever creating a competing version in the first place. Most modern CMS platforms and SEO plugins do this automatically.
Getting canonical tags right is one of the more effective fixes for duplicate content, and it works alongside — not instead of — a properly configured redirect strategy for URLs that should no longer be reachable at all.
Related reading
Most duplicate content is not copied text — it is the same page reachable at more than one URL. Here is how to find and fix it.
What is the difference between a 301 and a 302?One says the move is permanent, the other says it is temporary — and search engines treat those two claims very differently.
How to create and submit a sitemapWhat a sitemap actually does, how to build a valid one, and where to submit it once it exists.
Does HTTPS affect SEO?Google has confirmed it counts, though as a lightweight signal. The larger effect is what happens without it.