Technical Implications of “www” in URLs: Best Practices for Domain Redirection (301 vs Non-www)

Originally, "www" served as a standard subdomain to identify web servers in the early internet (pre-2000s). This convention emerged because:

Different services often ran on separate subdomains (ftp.example.com, mail.example.com)
Helped with DNS load balancing when web traffic needed dedicated infrastructure

Today, the "www" prefix has these implications:

// DNS configuration example showing CNAME flexibility
www    IN  CNAME   example.com.  ; Allows separate CDN configuration
@      IN  A       192.0.2.1     ; Root domain record

Key technical factors in 2023:

Cookie Scope: www.domain.com sets cookies for all subdomains (*.domain.com)
CDN Configuration: Many CDNs recommend using www for easier DNS setup
SSL Certificates: Wildcard certs (*.domain.com) cover both variants

For Apache servers:

<VirtualHost *:80>
    ServerName example.com
    Redirect 301 / http://www.example.com/
</VirtualHost>

For Nginx:

server {
    listen 80;
    server_name example.com;
    return 301 $scheme://www.example.com$request_uri;
}

Search engines treat these as separate URLs without redirection:

// Google Search Console treats them as separate properties
// Recommended verification method:
<meta name="google-site-verification" content="..." />

Testing with curl shows redirect overhead:

$ curl -I https://example.com
HTTP/2 301 
location: https://www.example.com
...
# Adds ~100-300ms latency per request

Current breakdown among top sites:

53% use www (Google, Facebook, Amazon)
47% use bare domain (Twitter, GitHub, Netflix)

Choose one canonical version (www or non-www)
Set up 301 redirects in server config
Verify in Google Search Console
Update sitemap.xml and robots.txt
Test all redirect chains with curl -L

Originally, "www" (World Wide Web) served as a subdomain to distinguish web servers from other services like FTP (ftp.example.com) or email (mail.example.com). In the early internet, this naming convention helped organize different services under a domain.

Today, the www prefix is largely optional due to:

HTTP/HTTPS becoming the dominant protocol
DNS improvements allowing flexible record configurations
Simplified user expectations (users often omit www)

For Apache (.htaccess):


# Redirect www to non-www
RewriteEngine On
RewriteCond %{HTTP_HOST} ^www\.example\.com [NC]
RewriteRule ^(.*)$ https://example.com/$1 [L,R=301]

For Nginx:


server {
    listen 80;
    server_name www.example.com;
    return 301 $scheme://example.com$request_uri;
}

Technical advantages of using the bare domain:

Shorter URLs (better for sharing and memorability)
Reduced cookie overhead (cookies set on example.com apply to all subdomains)
Simplified DNS configuration (fewer CNAME records needed)

Cases where www could be beneficial:

When using CDNs that require CNAME records
For large-scale deployments needing cookie isolation
When maintaining legacy system compatibility

Best practices for search engines:

Choose one version as canonical (301 redirect the other)
Consistently use your chosen version in all links
Verify both versions in Google Search Console

Set up proper 301 redirects (code examples above)
Update all internal links to your preferred version
Configure SSL certificates for both versions
Update Google Search Console and Analytics settings