The analysis of original and secondary content through the 'canonical' attribute.

Canonical Tab

The rel=”canonical” element helps specify a single preferred version of a page when it is available through multiple URLs. It is a suggestion to Search Engines to avoid duplicate content by consolidating indexing and link properties into a single URL for use in ranking.

The canonical link element should be placed in the document header or using HTTP rel=”canonical” headers.

The “canonicals” Tab shows canonical link elements and HTTP canonicals discovered during a scan by providing the following data in columns:

  • Address: the scanned URL.
  • Occurences: The number of canonical links found (either via the link element or HTTP).
  • Indexability: shows whether the URL is indexable or non-indexable.
  • Indexability Status: the reason why a URL is not indexable. For example, if it is canonized to another URL.
  • Canonical Link Element 1/2 etc: all instances related to canonical links.
  • HTTP Canonical 1/2 etc: all canonical instances issued via HTTP.
  • Meta Robots 1/2 etc: information about the Meta robots found on the URL.
  • X-Robots-Tag 1/2 etc – X-Robots-tag data: the Seo Spider finds all instances if there are more than one.
  • rel=”next” and rel=”prev”: the Seo tool collects these HTML link elements designed to indicate the relationship between URLs in a paginated series.

Canonical Card Filters

This tab includes the following filters:

  • Contains Canonical: identifies whether canonical URLs are present in the pages (either via link element, HTTP header, or both). The result could correspond to a self-referenced canonical URL where the page URL is the same as the canonical URL (Self Referencing), or it could be “canonicalized,” where the canonical URL is different from the page URL.
  • Self Referencing: the URL has a canon that is the same URL as the scanned page (thus, it is self referenced). Ideally, only canonical versions of URLs should be linked internally, and each URL should provide a canonical self-referenced to help avoid any potential duplicate content issues that may occur.
  • Canonicalised: the page contains a canonical URL other than itself. The URL is “canonicalized “to another HTML page. This means that Search Engines are instructed not to index the page, and Ranking should be assigned to the canonical target URL.
    In a perfect world, a website would not need to canonicalize any URLs since only canonical versions should be linked, but they are often required due to various circumstances beyond control, and to prevent duplicate content.
  • Missing: there are no “canonical” links either as a link element or by HTTP header. In this case, Google identifies what it thinks is the best version or URL implying unpredictability of ranking.
  • Multiple: we are in the presence of multiple canonical sets for the same URL (either multiple link elements, HTTP header, or both combined). This can lead to unpredictability, since there should only be a single canonical URL set by a single implementation (link element or HTTP header) for each page.
  • Non-Indexable Canonical: the canonical URL is a non-indexable page, i.e., not responsive with status code 200. This filter includes the canonical blocked by robots.txt, no response, redirect (3XX), client error (4XX), server error (5XX) or ‘noindex’.
Seo Spider Tab