Free Toolschevron_rightTechnical SEOchevron_rightCanonical Tag Checker
verified
Technical SEO · Free Tool

Free Canonical Tag Checker

Canonical tags tell Google which version of a page is the "master" — a wrong canonical can send your link equity to the wrong URL. This tool checks whether your canonical is self-referencing, matches the request URL, aligns with your OG URL, and uses HTTPS consistently.

What This Tool Checks

  • check_circleCanonical URL detection from <link rel="canonical"> tag
  • check_circleSelf-referencing check: does the canonical point to the same page?
  • check_circleHTTP vs HTTPS consistency: canonical should always use HTTPS
  • check_circlewww vs non-www consistency check
  • check_circleOG URL alignment: og:url should match the canonical URL
  • check_circleMissing canonical detection
lightbulb

Why This Matters for SEO

Canonical tags are how you consolidate ranking signals when similar or duplicate content exists at multiple URLs. Without proper canonicals, Google may split your PageRank across URL variants (with/without trailing slash, HTTP/HTTPS, www/non-www, filtered/sorted versions). A canonical pointing to the wrong page sends your link equity to a URL that can't rank — wasting all your backlink effort.

Want this audit running on every page of your site, every day? See PerfBee Site Crawler — Audit meta tags, canonicals, and schema across every page automatically.

Frequently Asked Questions

What is a canonical tag?expand_more
A canonical tag (written as <link rel="canonical" href="URL">) is an HTML element that tells Google which URL is the preferred, authoritative version of a page when similar content exists at multiple URLs. For example, if your product is accessible at /product/123, /product/123?color=red, and /product/shirt-123, a canonical on all three pointing to /product/shirt-123 tells Google to index and rank only the clean URL.
When should I use a canonical tag?expand_more
Use canonical tags when: you have URL parameters creating duplicate pages (filters, sorting, tracking), you have print-friendly or AMP versions of pages, you have content accessible via multiple URL paths, you have paginated content and want to consolidate signals to the main page, or you're syndicating content to other sites and want the original to rank. For unique pages with a single URL, a self-referencing canonical is best practice.
What is a self-referencing canonical?expand_more
A self-referencing canonical is when a page's canonical tag points to itself. For example, page at /blog/article has a canonical pointing to /blog/article. This is best practice even for pages without duplicates — it explicitly tells Google "this is the correct URL to index" and prevents Google from choosing a different variant. Every page should have a canonical tag, even if self-referencing.
What is a canonical chain and why is it bad?expand_more
A canonical chain occurs when page A has a canonical pointing to page B, and page B has a canonical pointing to page C. Google generally follows canonical chains, but they can reduce the effectiveness of signal consolidation. The best practice is to point all duplicate/variant URLs directly to the final canonical URL, never through intermediate pages. Chains also indicate your internal linking may be inconsistent.
rocket_launchFree forever plan — no credit card required

Find canonical issues across your whole site

Canonical mismatches are subtle and hard to spot manually. PerfBee crawls every page and maps canonical relationships — flagging chains, conflicts, and missing canonicals. Get daily crawl reports, broken link alerts, Core Web Vitals tracking, and AI fix suggestions — across your entire site.

  • checkCrawl unlimited pages — daily, automatic
  • checkBroken link detection across your whole site
  • checkCore Web Vitals & Lighthouse audits per page
  • checkAI-powered code fix suggestions
  • checkWhite-label PDF reports for clients
  • checkEmail alerts for new issues & downtime
Audit Canonicals Site-Widearrow_forwardView Pricing

Trusted by SEO teams, agencies, and developers worldwide.

Related Tools

image_search
Image Alt Text Checker
language
Hreflang Checker
data_object
Schema Markup Validator

More Free Tools

link_off
Broken Link Checker
speed
Website Speed Test
monitor_heart
Core Web Vitals Checker
swap_horiz
Redirect Checker
gpp_maybe
Robots.txt Tester
map
XML Sitemap Validator
appsView All Free SEO Tools