Point Google at the one pagethat should rank.
Every duplicate of a page, a tracked link, a sorted filter, an http and https version, splits your ranking signals across copies that compete with each other. A canonical tag tells search engines which URL is the real one and pours all that equity into it. Paste your page, strip the junk parameters, and copy a tag you can drop straight into the head.
Your page URL
Paste the exact, full address of the page. The canonical must be absolute, with the protocol and domain, never a relative path.
Your canonical tag
Drop this in <head>
<link rel="canonical" href="https://example.com/shoes" />
Cleaned to https://example.com/shoes
Canonical check
Valid absolute canonical
Absolute URL with protocol and domain, ready to drop into the head.
Tracking params stripped
Removed utm_source, fbclid so every tracked share consolidates onto the clean page.
Point at a live 200 URL
Make sure this URL returns 200, not a 301 redirect or a 404. Canonicalizing to a redirect gets ignored.
One tag, in the head
Place exactly one canonical inside <head>. Two tags cancel each other out; audit your CMS and SEO plugin for duplicates.
Your move
Canonicals stop the leak. I find where the equity should pool.
Your canonical points at https://example.com/shoes (tracking params stripped).
Clean canonicals are table stakes, the real wins come from a site architecture that funnels authority to the pages that sell. Send me your site and I'll show you, free, where your ranking signals are scattering and which pages I'd consolidate them onto first. You keep the audit whether you hire me or not.
Plain English
Duplicate content isn't a penalty. It's a leak.
A canonical tag is a single line of HTML, `<link rel="canonical" href="..." />`, that you put in the `<head>` of a page to declare the preferred, authoritative URL for that content. When the same or near-identical content is reachable at multiple addresses, search engines have to guess which one to index and rank. The canonical takes the guesswork away: it says 'this is the master copy, attribute everything here.'
This matters more than most people realize because the web manufactures duplicates constantly. A product page lives at a clean URL, but also at every variant with a tracking parameter (`?utm_source=newsletter`), every faceted filter, the http and https versions, the www and non-www versions, the trailing-slash and no-slash versions, and the print view. To a crawler those can all look like separate pages competing for the same query. Links and authority scatter across them instead of stacking on one.
The fix is to canonicalize. Every page should carry a canonical tag, and in the common case it should point at itself, a self-referencing canonical, with the clean, parameter-free, absolute URL you actually want indexed. This tool builds that tag, lets you strip the tracking parameters that create phantom duplicates, and flags the mistakes (relative URLs, multiple tags, canonicalizing to a redirect) that silently turn the tag into a no-op.
The formula
<link rel="canonical" href="https://example.com/clean-page" />
A visitor lands on https://example.com/shoes?utm_source=ig&fbclid=abc123. Left alone, that tracked URL can get indexed as a separate page. Add a canonical pointing at https://example.com/shoes and every signal, the link, the crawl, the ranking, consolidates onto the one clean address.
Your canonical isn't working. Here's why.
The href is a relative path.
A canonical must be an absolute URL with protocol and domain. `/shoes` is ambiguous; some crawlers resolve it wrong or ignore it. Always write the full https://domain.com/path.
Tracking parameters are still in the URL.
utm_*, fbclid, and gclid create infinite phantom duplicates of one page. Canonicalize to the clean URL without them so every tracked share consolidates onto the real page.
There's more than one canonical tag.
Two canonical tags on a page cancel each other out, search engines ignore both and pick for themselves. Ship exactly one, and make sure no plugin or template is injecting a second.
The canonical points to a redirect or a 404.
Canonicalizing to a URL that 301s or returns 404 sends a contradictory signal and gets ignored. Point at the final, live 200 URL, the destination, never the hop.
Protocol or trailing slash doesn't match the live page.
If your site serves https with no trailing slash, the canonical must say exactly that. http vs https or /page vs /page/ mismatches look like a different URL and dilute the signal you were trying to consolidate.
How to canonicalize without shooting yourself in the foot
01Self-reference by default
Every indexable page should carry a canonical that points at its own clean URL. It's the cheapest insurance against parameter and protocol duplicates, and it costs you nothing.
02Always use absolute URLs
Protocol, domain, and path, every time. Relative canonicals are the single most common way the tag silently fails. `https://example.com/page`, never `/page`.
03Strip tracking parameters
Canonicalize to the version without utm_*, fbclid, gclid, and session IDs. Otherwise every campaign link spawns a competing duplicate of the same page.
04Pick one URL format and commit
Decide https vs http, www vs non-www, trailing slash vs not, lowercase, and make your canonicals, redirects, sitemap, and internal links all agree. Consistency is the whole game.
05Never canonical to a redirect
Point at the final 200 URL, not a page that 301s onward. A canonical to a redirect is a contradiction crawlers resolve by ignoring you.
06One tag, in the head, no exceptions
A single canonical, inside `<head>`. Two tags, or one injected in the body, both get discarded. Audit your CMS and SEO plugin so they aren't fighting.
07Don't canonicalize paginated or filtered pages to page one
Page 2 of a series isn't a duplicate of page 1. Self-reference paginated pages; only canonicalize true duplicates and parameter variants, or you'll deindex content you wanted found.
08Keep canonical and noindex apart
Don't put both on the same page, they send opposite instructions and confuse crawlers. Canonical says 'rank this one instead'; noindex says 'rank none of these.' Choose deliberately.
The vocabulary
- Canonical tag
- An HTML link element (rel="canonical") that names the preferred URL for a piece of content so duplicates don't compete.
- Self-referencing canonical
- A canonical tag whose href is the page's own clean URL. The recommended default for every indexable page.
- Duplicate content
- The same or near-identical content reachable at more than one URL. Splits ranking signals unless you canonicalize.
- Tracking parameter
- A query string like utm_source, fbclid, or gclid added for analytics. It creates a new URL that can be indexed as a duplicate.
- Absolute URL
- A full address including protocol and domain (https://example.com/page). Canonicals must be absolute, never relative.
- 301 redirect
- A permanent server redirect from one URL to another. Canonicals should point at the final destination, never at a URL that redirects.
Canonical tag questions, straight answers
A canonical tag is a single line of HTML, <link rel="canonical" href="..." />, placed in a page's <head> that tells search engines which URL is the authoritative version when the same content exists at multiple addresses. It consolidates ranking signals onto one URL instead of letting duplicates split them.
Keep going
A calculator tells you what. A call tells you what to do about it.
Send me the account behind these numbers. I'll tell you straight where the money's leaking and what I'd fix first — free, and you keep it whether you hire me or not.