top of page
  • Writer's pictureBrent Payne

Mismatched canonical tag in HTML and HTTP header

The URL under review exhibits discrepancies as it includes canonical tags specified within both the HTML code and the HTTP header, with each tag pointing to a different URL.

Why is this important?

When search engines discover canonical tags that do not match, they might disregard any canonical instructions. This could lead to the unintended indexing of content such as duplicates that the site owner may prefer to keep unindexed.

What does the Optimization check?

The Optimization is activated when an internal URL is found to contain mismatched canonical link elements present both in the HTML of a page and in the HTTP header served with the page.

Note: When this Optimization is activated, it simultaneously activates the Optimization: Canonical tag in HTML and HTTP header.

Examples that trigger this Optimization:

This Optimization would be activated for this URL if it contained the following inconsistencies:

Canonical link in the <head> to one URL:

<link rel="canonical" href="" />

AND an HTTP Header canonical link directed to a different URL:

HTTP/... 200 OK...Link: <>; rel="canonical"

How do you resolve this issue?

Firstly, identify the accurate canonical URL and confirm that this is the sole reference employed.

Additionally, avoid specifying canonical tags in both the HTML and HTTP header, as this can potentially introduce errors such as the aforementioned inconsistency. Hence, it is advisable to eliminate one form of canonical tagging.

Choose a sole method for indicating canonicals and adhere to it throughout. It may be necessary to consult with your website development team to ascertain the most manageable method for your website.


Recent Posts

See All

ClubReq Gets A Link (Because They Asked)

I am a mentor for Techstars and have been for over 10 years. In those ten years I have mentioned to startups to ask ANYONE and everyone that they meet to link to their site. Yet, in all those times on


bottom of page