Skip to main content
Free SEO tool

Canonical Checker — Free Tag & URL Test

A canonical checker reads the rel=canonical tag in live HTML and flags missing, relative, conflicting, or off-page canonicals. Scan a URL to see which version Google and AI crawlers should treat as the official page.

Format: Absolute HTTPS URL Count per page: Exactly one Self-reference: Preferred on unique pages

Website URL to analyze

About this tool

A canonical checker reads the rel=canonical tag in live HTML and flags missing, relative, conflicting, or off-page canonicals. Scan a URL to see which version Google and AI crawlers should treat as the official page.

Validate rel=canonical tags so search engines index your preferred URL when duplicates, parameters, or HTTP/HTTPS variants exist.

What we check

In your free report

  • rel=canonical link tag presence in HTML head
  • Whether canonical is self-referencing or points elsewhere
  • HTTP vs HTTPS and www vs non-www consistency
  • Conflicts with meta robots noindex on the same page
Format Absolute HTTPS URL
Count per page Exactly one
Self-reference Preferred on unique pages
Best practices

Recommendations from official docs

One canonical per indexable page

Google expects a single canonical URL per page. Multiple conflicting canonicals cause Google to ignore them and pick its own preferred URL.

Use absolute URLs

Canonical href values should be absolute (https://example.com/page), not relative paths — relative canonicals are error-prone across environments.

Canonicalize parameter and duplicate URLs

UTM tags, sort filters, and print versions should canonicalize to the clean primary URL to consolidate ranking signals.

Do not canonicalize to a noindex page

Pointing canonical to a noindex URL sends mixed signals. The indexable page and its canonical target should both be crawlable and indexable.

How to fix

Step-by-step action plan

  1. 1 Add <link rel="canonical" href="https://yourdomain.com/preferred-url"> in <head>.
  2. 2 Pick one preferred host (HTTPS, www or non-www) and redirect others with 301.
  3. 3 Set canonical on parameterized URLs to the clean version without query strings.
  4. 4 Remove duplicate canonical tags injected by plugins or conflicting SEO tools.
  5. 5 Verify in Google Search Console URL Inspection which URL Google selected as canonical.
Official references

Learn more from the source

Related guides

Learn how to improve these signals

Title and canonical basics On-page signals that go with rel=canonical → Noindex checker A noindex tag beats a perfect canonical → How to whitelist OAI-SearchBot ChatGPT search crawler robots.txt + Cloudflare IPs → What is GPTBot? Allow or block OpenAI training crawls →
Related tools

Fix what this scan finds

AI Crawler Checker → Sitemap Checker → Indexability Checker → Meta Title Checker →
Run full-site audit (up to 100 pages)

Need help fixing AI SEO issues?

Optimize your website for AI SEO, ChatGPT Search, Google AI Overviews, GPTBot, llms.txt, robots.txt, schema, and crawlability.

Hire Mubashir to fix crawl issues

Questions about this tool

How do I check a website for canonical tags?

Paste the URL into this canonical checker. We read the live HTML for rel=canonical, then flag missing, self-referencing, or conflicting tags.

Why do canonical tags matter?

They tell search engines which URL is preferred when duplicate or similar pages exist, reducing index bloat.

Does this check the HTTP Link canonical header?

This checker reads the HTML rel=canonical tag on the live page. Confirm HTTP Link headers in your server config or Search Console URL Inspection if you set canonicals outside HTML.

What if my canonical points elsewhere?

Search engines may index the canonical target instead of the scanned URL. Align canonicals with your intended indexable page.