Audisto Crawler Hints
Canonical Tag Checker Duplicate Content Prevention Tool
What is the canonical checker for
Prevent Duplicate Content: Detect issues with canonical tags including invalid URLs, improper placement, and conflicting implementations that could create SEO problems.
Ensure Proper Implementation: Find technical issues like relative URLs, cross-domain canonicals, and dynamic canonical modifications that affect search engine interpretation.
Maintain SEO Best Practices: Identify proper canonical usage and validate implementation across your website to maintain clear signals for search engines.
Monitor Canonical Health: Track changes in canonical implementation to prevent duplicate content issues and maintain consistent SEO signals.
How to check canonical tags issues at scale
Canonicals protect your SEO
Proper canonical implementation is crucial for preventing duplicate content issues and maintaining SEO effectiveness. Our analysis helps you ensure correct canonical usage across your website. While our quick check provides immediate insights for single pages, our full crawler ensures consistent canonical implementation across your entire website.
Critical Canonical related hints
<link rel=canonical>: Contains malformed or empty href
This hint identifies all occurrences of canonical elements that contain an invalid target URL.Learn more
<link rel=canonical>: Found outside <head>
A canonical element was placed outside the <head> section and so search engines will ignore it.Learn more
<link rel=canonical>: Found twice
More than one canonical element was found, either as a <link> tag with rel="canonical" or an according link header.Learn more
<link rel=canonical>: Found twice and differs
More than one canonical element has been found, either as a <link> tag with rel="canonical" or an according Link header. Additionally, they specify different targets.Learn more
Problem indicating Canonical related hints
<link rel=canonical>: Points to other URL
If the canonical element is found and it points to a different URL, the URL is flagged with this hint.Learn more<link rel=canonical>: URL is not absolute
If the canonical element specifies a URL relative to the document's URL, the document's URL is flagged with this hint.Learn moreRendering: Canonical URL changed
This hint detects all HTML documents where the canonical URL is modified or set dynamically during rendering.Learn more
Informational Canonical related hints
<link rel=canonical>: Host change
This hint identifies all URLs that have a canonical link pointing to another host.Learn more<link rel=canonical>: Not found
A canonical element has not been found: neither a <link> tag with rel="canonical" nor an according link header. This may be intended.Learn more<link rel=canonical>: Protocol change
This hint identifies all URLs that have a canonical link that changes the protocol from HTTP to HTTPS or vice versa.Learn more<link rel=canonical>: To external URL
This hint identifies all URLs that have a canonical link that leads to a URL that is not within the crawled domain(s).Learn more
Good practice Canonical related hints
<link rel=canonical>: Found
A canonical element has been found, either as a <link> tag with rel="canonical" or an according link header.Learn more<link rel=canonical>: Points to same URL
If the canonical element is found and points to the same URL, the URL is flagged with this hint.Learn more