Should you really care about the WWW vs Non-WWW redirect?

Why does Google care about the WWW vs Non-WWW distinction?

Google treats www.example.com and example.com as two distinct entities. If both versions respond with identical content without redirection, the engine may index both.

This duplication poses several problems: PageRank gets fragmented between both versions, crawl budget is wasted exploring redundant URLs, and ranking signals (backlinks, anchors, social signals) become dispersed. The result? A measurable loss of visibility.

What does proper configuration technically entail?

A clean configuration relies on three pillars. First, define a unique canonical version (WWW or non-WWW) in Google Search Console. Second, implement a permanent 301 redirect server-side from the non-canonical version to the canonical one.

Third, reinforce this directive with canonical tags on each page to eliminate any ambiguity. These three mechanisms work in synergy: the 301 redirect guides Googlebot, the canonical tag acts as a safety net, and the Search Console declaration confirms your intention.

What are the most common configuration mistakes?

The worst mistake is to leave both versions active without redirection or canonical. Another trap is implementing a JavaScript redirect instead of a server redirect. Google will eventually understand, but with a consolidation delay that can take weeks.

Some sites configure chain redirects (non-WWW → WWW → HTTPS, for example), multiplying unnecessary hops. Others declare one version in Search Console but redirect to the other — guaranteed confusion. Finally, forgetting to update XML sitemaps with the correct canonical URLs delays indexing.

• Choose a canonical version and stick with it absolutely across all environments
• 301 redirect server-side (Apache, Nginx, CDN) never in JavaScript or meta refresh
• Declare the canonical version in Google Search Console and Bing Webmaster Tools
• Add canonical tags on all pages pointing to the canonical version
• Update sitemaps exclusively with the canonical URLs

Does this Google directive truly reflect ground observations?

Yes, this guideline is one of the few instances where Google remains perfectly consistent with what we observe. Sites that leave both versions active experience measurable PageRank dilution. Recent audits consistently show a 15-25% increase in organic traffic after consolidating to a single version.

Google generally consolidates signals to the version it detects as primary (often the one with the most backlinks), but this process takes time. Rather than letting the algorithm guess, it is better to enforce your decision with a clean 301. Sites that wait passively lose weeks of visibility during the floating phase.

Is there any difference in SEO performance between WWW and non-WWW?

No, there is none. Google grants no intrinsic advantage to either version. The choice is based on technical or marketing preferences. WWW simplifies certain DNS configurations (notably to isolate cookies from a naked domain), but the SEO impact is strictly zero.

What matters is absolute consistency. Once a choice is made, all elements (internal backlinks, sitemap file, canonical links, redirects) must point to this single version. A site that alternates between the two in its internal linking creates unnecessary friction for Googlebot.

What special cases complicate this simple rule?

Multi-domain or multi-language sites can sometimes pose issues. If you use geographic subdomains (fr.example.com, uk.example.com), each subdomain must decide on its own WWW/non-WWW management. It is impossible to declare a global rule in Search Console — each property must be configured separately.

Domain migrations add a layer of complexity. If you are moving from old-domain.com to new-domain.com, you must decide before migration which version (WWW or non-WWW) will be canonical on the new domain. Some sites migrate forgetting this detail, creating a double penalty: migration AND duplication. [To be verified]: Google claims to consolidate signals automatically, but ground data shows this consolidation can take 6-8 weeks without explicit redirection.

How can I check my site's current configuration?

Start by manually testing the four variants: http://example.com, http://www.example.com, https://example.com, https://www.example.com. Each non-canonical variant should immediately redirect with a 301 to the canonical version. Use your browser's Developer Tools (Network tab) to verify that the redirect returns an HTTP 301 code, not a 302 or 307.

Next, inspect about ten deep pages (not just the homepage) to ensure that the rule applies everywhere. Also check the canonical tags in the source code: they should uniformly point to the WWW or non-WWW version. Finally, consult Search Console to confirm that the declared property corresponds to the canonical version.

What is the procedure to correct a bad configuration?

If your site currently responds on both versions, first choose which one will be canonical. Deciding factor: look at your backlinks and your Analytics history to see which version naturally receives the most traffic. Once decided, implement the 301 redirects server-side (htaccess file for Apache, Nginx configuration, Cloudflare rules).

Then, add canonical tags on all pages. Update your XML sitemap to list only the canonical URLs, and resubmit it in Search Console. Declare (or re-declare) the property corresponding to the canonical version in Search Console and Bing Webmaster. Monitor coverage reports for 2-3 weeks to ensure that Google correctly consolidates the URLs.

What mistakes should be avoided when ensuring compliance?

Never create chain redirects. If you need to redirect HTTP to HTTPS and non-WWW to WWW, do it in one jump: http://example.com should redirect directly to https://www.example.com, not through an intermediate step. Each additional jump dilutes the transmitted PageRank and slows down crawling.

Avoid JavaScript or meta refresh redirects as well — Google follows them, but with a significant processing delay. Regarding content, don’t forget to update internal links: even if the redirects work, an internal linking structure that heavily points to the wrong version forces Googlebot to follow thousands of unnecessary redirects, wasting your crawl budget.

• Manually test the 4 variants (HTTP/HTTPS × WWW/non-WWW) and check 301 codes
• Implement redirects server-side (Apache, Nginx, CDN) never in JavaScript
• Add consistent canonical tags on all pages
• Declare the canonical version in Google Search Console and Bing Webmaster Tools
• Update the XML sitemap with exclusively the canonical URLs
• Audit and correct internal links to point directly to the canonical version