Who this helps
- Developers reviewing head templates
- Editors investigating duplicate page addresses
Blog Utility
Canonical URL Checker
Quickly check canonical tag issues in HTML head code, including missing tags, duplicate tags, href format, and absolute URL usage.
Canonical Tag Check
Check whether a rel="canonical" tag exists.
URL Format Check
Check absolute URLs, http/https format, and empty href values.
Prevent SEO Duplication
Clearly tell search engines which URL is the representative page.
Enter HTML Head Code
Paste the page head area or full HTML code to analyze the canonical URL status.
0 chars
Enter HTML code and click the Canonical Check button.
Check Result
Check the canonical tag count, href value, URL format, and status.
0
Canonical Tags
0
Valid URLs
0
Needs Check
| No. | Canonical URL | Status |
|---|---|---|
| The check result will appear here. | ||
Checking canonical tags in pasted HTML
Find missing, duplicate and questionable canonical links before publishing. The checker reads supplied HTML; it cannot confirm which canonical URL a search engine has selected.
When to use this tool
- Find a second canonical added by a plugin.
- Check a relative, HTTP or query-bearing canonical URL.
From input to a checked result
- 1
Copy the final HTML or its head section.
- 2
Paste no more than 500,000 characters.
- 3
Run the check and compare the tag and issue counts.
- 4
Review each href against the intended representative URL.
- 5
Inspect the live response, redirects and indexing status separately.
One representative URL
- Input
- <link rel="canonical" href="https://example.com/article/">
- Result
- One tag with a valid HTTPS URL
This confirms basic format only, not availability or indexing.
Conflicting representatives
- Input
- <link rel="canonical" href="https://example.com/a/"><link rel="canonical" href="https://example.com/b/">
- Result
- Duplicate canonical warning
Resolve the template conflict and retain the intended representative.
How it works
DOMParser reads link elements whose rel contains canonical. Each row reports its first applicable issue: absent or empty href, non-HTTP(S) absolute URL, HTTP, fragment, query string or multiple tags.
Limitations
- Query parameters can identify legitimate content; the warning requires context.
- Only the pasted markup is examined, without HTTP headers or redirects.
- A format pass does not prove that a search engine will adopt the URL.
Your data
Pasted HTML is processed locally. Remove sensitive values before copying source into any utility.
References
Related tools
- sitemap.xml Generator
Convert a URL list into XML, resolving relative paths and removing duplicates. Select canonical, indexable pages before generating the file; the tool cannot verify their live status.
- SEO Head Checker
Inspect pasted head code for missing or duplicate metadata and basic URL issues. The percentage is a win-j checklist score, not a Google score or a prediction of indexing.
Frequently asked questions
Is a query string always wrong?
No. Keep it when it defines the intended canonical content; remove tracking parameters only when appropriate.
Does the checker open my URL?
No. It examines the href text and supplied tags.
Why is only one issue shown in a row?
The checks have an order. Fix the reported issue and run the check again to see the next applicable warning.