Audisto Crawler

Rel canonical checker tool to automatically validate canonical link tags

  • Analyze how rel canonical links influence the indexability of HTML documents
  • Detect host and protocol changes and canonical links pointing to external URLs
  • Identify malformed, inaccurate, duplicate or missing rel canonical definitions
  • Debug complex canonical groups and test for best-practice compliance of linked pages

How to check rel canonical on website

Photo of Tobias Schwarz
Tobias Schwarz, CTO Audisto:

Control over the rel canonical links on your website is important for indexing and to avoid duplicate content

Our rel canonical validator checks for common errors, missing canonical links and reports the indexability of your documents based on noindex directives and canonicals to other URLs. Correcting canonical mistakes contribute to a better crawling often resulting in a more up to date search index.

Rel canonical tester features

Indexability of HTML documents report from Audisto

Automated discovery

Rel canonical links are automatically detected by the canonical tool during a crawl, when found in the HTML head and the HTTP header.

Indexability of documents

The indexability of each document is determined by the canonical tag checker trough looking at the canonical target and the meta robots directive, if present.

Analyze PageRank tied up in canonicals

Review how much of your internal authority is bound to canonical pages and visualize the impact via PageRank flow.

Debug complex canonical groups

Canonical group report from Audisto Crawler. Shows groups, hints, group members and a graph chart of the canonical link graph.

Analyze full canonical groups, not single tags

All pages that are linked via canonicals are automatically grouped and will be tested for best practice of canonical compliance.

Understand loops or canonical chains

With the helpful visualization of the canonical link graph, you identify conflicts, incorrect URLs or canonical abuse easily. Complex issues can be understood at a glance.

Safeguard the designated canonical leader

Analyze within complex canonical groups if the canonical leader is the strongest page. Ensuring your canonical leader is a deliberate decision and remains stable.

Secure cross-domain republishing

Analyze canonical leaders across different domains and ensure your legitimate cross-domain content duplication is following your syndication strategy without problems.

Check for common rel canonical errors

Example of a canonical hints report from Audisto

Incorrect canonical links

Detect malformed or empty canonical links or links that are placed outside the HTML head, by performing a rel canonical check.

Duplicate canonical tags

Find URLs that have more than one canonical element set, and find out if they are conflicting.

Unnecessary documents

Discover documents that can potentially be replaced with a redirect, because the canonical is either a protocol or host change, using our canonical URL checker.

Unreachable documents

Perform a risk check for documents that might get isolated and stop ranking, based on having only long-term canonical links.