SEO finding
The canonical points at the wrong place, or links ignore it
SEO Warning Severity: High
Part of the audit Canonical tags. Finding id: seo.canonicalTarget.
What it costs you
A canonical that leads to an error, a redirect or a noindex page cannot be followed, so the search engine picks the address to index itself.
What to do
Point the canonical at a URL that answers 200, is indexable and is the address you want in search results.
What it checks
- Preferred address redirects elsewhere
- Preferred address does not load
- Preferred address is hidden from search
- Preferred address on another website
- Preferred address uses a different protocol
- Page and server give different preferred addresses
- Links point to non-preferred addresses
How to fix it
Send the canonical from one place
- Run curl -sI [url] and read the Link header.
- Find which system sends it: web server, CDN or application.
- Remove the header or the tag, so one value is left.
How to check: curl -sI [url] shows no Link header with rel=canonical, or the same address as the tag.
Confirm the canonical on another domain
- Ask whoever owns the content whether [detail] is meant to be the original.
- If not, set the canonical of [url] to its own address.
How to check: Recrawl and run this rule again, or mark the finding as intended.
Link to the canonical address
- Find the links to [url], starting with the page named in the finding.
- Change them to [canonical]. Links printed by a template are fixed once in the template.
How to check: Recrawl and run this rule again.
Point the canonical at the final, indexable URL
- Open the canonical address. It must answer 200 without a redirect and must not be noindex.
- If it redirects, use the address it ends at. Use https when the site is served over https.
How to check: curl -sI on the canonical address returns 200; then recrawl and run this rule again.
A real case
Hynek Schlawack's site template carried a canonical tag that pointed every page at the homepage, so Bing and Yandex dropped his other pages from their indexes. He fixed the line on 24 December 2020 and the pages were not fully back until March 2021.