WWW vs Non-WWW Canonical Checker
A WWW vs non-WWW canonical checker inspects both hostname variants (https://www.example.com and https://example.com) to ensure your web server enforces a single preferred domain version. One variant must permanently 301-redirect to the other, preventing search engines from seeing duplicate versions and splitting link equity.
Tests both https://example.com and https://www.example.com to verify canonical consolidation.
What is a WWW vs non-WWW canonical checker and when should you use it?
From a technical networking perspective, `www.example.com` and `example.com` are two distinct hostnames. If a web server responds with a 200 OK status code on both addresses without a redirect, search engines treat them as two independent websites serving duplicate content. This divides backlink authority, confuses canonical indexing algorithms, and dilutes organic keyword rankings. This utility probes both hostnames in parallel, verifies whether a permanent 301 redirect consolidates traffic to your chosen canonical preference, and provides server configuration fixes. For directory-level URL hygiene, use our Trailing Slash Consistency Checker and Redirect Chain Checker, or verify protocol redirection with the HTTP to HTTPS Redirect Checker.
How do you use it?
- Enter your domain name (without www or protocol, such as example.com).
- Click the Compare Hostname Variants button to test both addresses simultaneously.
- Review the side-by-side status codes and destination URLs for both variants.
- Confirm that one hostname permanently redirects (301) to the other canonical version.
- Copy the supplied Apache or Nginx rewrite directives if both versions respond independently.
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Result interpretation & practical applications
When evaluating the output of the WWW vs non-WWW canonical checker, review the parsed metrics against your specific site architecture. Outputs are formatted for direct implementation into your HTML source, web server configuration, or Google Search Console audit files.
Always inspect generated values for contextual nuance. Automated tools highlight structural patterns, but manual verification confirms that technical directives align with your overarching SEO strategy.
Technical rules and limitations
- Google does not favor www over non-www; consistency is what matters for technical SEO consolidation.
- The non-preferred version must return an HTTP 301 Moved Permanently redirect to the preferred version.
- Both hostnames should resolve over HTTPS to maintain transport encryption.
- Self-referencing canonical link tags must match the enforced server-level hostname preference.
Common mistakes and troubleshooting
- Allowing both www and non-www to respond with 200 OK, halving incoming backlink PageRank equity.
- Configuring www redirects in WordPress settings while hosting DNS records lack a CNAME or A record for the secondary host.
- Creating a redirect loop where non-www points to www on HTTP, while www points back to non-www on HTTPS.
- Forgetting to configure Google Search Console property sets for both domain variations.
No tool can promise how a search engine will crawl, index, or rank your pages. This tool generates and validates code against documented technical specifications; you determine where to deploy it, and you should always test changes on staging environments first. Google publishes extensive guidelines in Search Central on evaluating third-party SEO tools and advice. Learn more about our technical testing standards on our about us page, or explore full site audits on our pricing page.
Related free tools & workflows
Browse all Technical SEO Audit Tools →Technical SEO Audit Workflows
Indexability & Crawling
Redirects & HTTP Headers
Authoritative Technical Documentation & Standards
This tool executes logic aligned with official technical documentation and search engine webmaster standards:
- Google Search Central Canonicalization Guide
Google Search Central: Consolidate Duplicate URLs
Primary engineering source and technical documentation.
- Google Search Central Redirects Documentation
Google Search Central: Redirects and Google Search
Primary engineering source and technical documentation.
WWW vs Non-WWW Canonical Checker questions
Is WWW better than non-WWW for SEO rankings? ↓
No. Google treats www and non-www equivalently. The only critical requirement is choosing one version as your canonical host and 301-redirecting the other.
Why does non-WWW sometimes have DNS advantages? ↓
Historically, root domains (non-www) could not use CNAME DNS records at the zone apex. Modern DNS providers now support CNAME flattening (ALIAS or ANAME records), eliminating technical differences.
How do I fix a duplicate WWW split in Nginx? ↓
Configure a dedicated server block in Nginx for the non-preferred hostname: server { server_name example.com; return 301 https://www.example.com$request_uri; }
Is this tool free? ↓
Yes. It is completely free to use and requires no registration or subscription.
Does this tool visit my website or store my files? ↓
No. It executes entirely in your local browser runtime. Your inputs and results are never stored or logged on our servers.
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