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— Free SEO tool

Canonical checker

The canonical tag tells Google which version of a page to show. Point it at the wrong place and the page you want can quietly drop out.

Free tool · Canonical checker

Check the canonical tag on every page

Put in your home page. The checker reads up to 50 pages and shows where each page’s canonical tag points, flagging missing, doubled or misdirected ones.

Pages come from your sitemap, or by following links from the home page if there isn’t one. Results aren’t stored anywhere. Pages built entirely with JavaScript may show as empty, because this reads the HTML your server sends.

01 How it works

What it checks

01

Missing canonicals

Not an error on its own: Google picks a canonical anyway. But a self-referencing canonical on every page removes the guesswork, especially with tracking parameters or www and non-www versions around.

02

More than one canonical

When a page sends conflicting canonicals, Google may ignore them all. This usually happens when a theme and an SEO plugin both add one.

03

Pointing somewhere else

A canonical to another URL asks Google to show that page instead. Right for duplicates and filtered versions; a problem if it’s on a page you want to rank.

Sources: Google: Consolidate duplicate URLs

02 Questions

What people ask

What is a canonical tag?

A line in the page’s head, <link rel="canonical" href="…">, that tells Google which URL is the main version when similar pages exist.

Does Google always follow the canonical?

No. Google treats it as a strong hint, alongside redirects, sitemaps and internal links. If the signals disagree, it may choose a different URL.

Should every page have a self-referencing canonical?

It’s good practice, and most platforms add one automatically. It stops tracking parameters and alternative versions being treated as separate pages.

03 More free tools

Noindex checkerPages telling Google not to index them, in the HTML or the headers.Sitemap checkerFind and validate the XML sitemap, then spot-check the pages it lists.Title tag checkerTitles that are missing, over 70 characters or copied across pages.

All free SEO tools →

— Next step

Start with a free SEO audit

Send me your site and you’ll get a short, honest read on what’s wrong. If you want the detail after that, the full audit is a paid piece of work, or part of a retainer.

Get the free audit Usually a reply within a working day.
  • 01The main things holding your site back, in plain English
  • 02Which of them are worth fixing first
  • 03Whether a full audit or a retainer makes sense, or neither