Canonical Tags: How a Wrong One Hides Your Page

In a page's code it looks like this:

It exists because the same page can often be reached at several addresses: with and without www, with a tracking parameter on the end, through a category path and directly. The canonical tag tells crawlers which one to treat as the original, so all the credit lands in one place instead of being split.

When it points at the wrong address, that credit lands on the wrong page. Yours disappears.

If your services page names your homepage as its canonical, assistants treat the services page as a copy. It won't be quoted, and it won't be cited. The homepage gets mentioned instead, and the homepage doesn't say what you charge or what's included.

The page looks perfectly fine to you. Nothing is broken, nothing is blocked. Google explains the mechanism if you want the detail, but the short version is: the tag is believed.

1. Check a few pages. Open a page, press Ctrl+U (Cmd+U on a Mac) to view the source, and search for canonical. Compare the address in the tag with the address in your browser bar.

• They match: correct. This is what every normal page should look like.
• They differ: the page is pointing credit elsewhere. Worth investigating.
• No tag at all: not ideal, but far less damaging than a wrong one.

Check your homepage, one services or product page, and one blog post. If all three are right, the rest usually are too.

2. Know which mismatches are fine. A product available in several colours may legitimately name one version as canonical. A printer-friendly page pointing at the normal page is correct. What isn't correct is a real, distinct page naming a different page as the original.

3. Fix the wrong ones. In most setups this means clearing a custom canonical that someone entered by hand, so the page falls back to naming itself. SEO plugins have a field for this, usually under an advanced section, and it should normally be left empty.

4. Reload and confirm the canonical now matches the address bar.

That's a template problem, not a page problem: the canonical tag is hardcoded somewhere in the theme instead of being generated per page. One fix in the template corrects the whole site. This is worth handing to whoever maintains your theme rather than editing page by page.