Does WWW still belong in URLs?

Years of debate rage on: should URLs include "WWW"? Tech giants like Google and Facebook redirect example.com to www.example.com, while others such as GitHub and DuckDuckGo prefer the opposite. This article explores the arguments for and against, delving into the history and technical implications.

The "WWW" Origins

The three "W"s stand for "World Wide Web," the technology that launched the internet as we know it. Using "WWW" as a subdomain originated from a convention of designating service types: www for web servers, ftp for FTP servers, and so on.

Concerns about WWW-less Domains

1. Cookie Leaks: A past concern was that subdomain.example.com could access cookies set by example.com, potentially problematic for web hosting providers. However, modern browser standards (RFC 6265) address this, rendering it largely irrelevant unless the Domain attribute is explicitly set or Internet Explorer is used.

2. DNS Complexity: Omitting "WWW" can complicate DNS setup, especially when using Canonical Name (CNAME) records. CNAME records cannot directly point to a root domain (e.g., example.com), potentially hindering email functionality (@example.com). However, workarounds like CNAME flattening offered by providers like Cloudflare mitigate this issue.

Advantages of WWW-less URLs

Advocates for dropping "WWW" cite simplicity and a minor performance boost (saving 4 bytes per HTTP request). While the performance gain is negligible for most sites, it can be significant for high-traffic platforms.

Advantages of Including "WWW"

Using "WWW" can improve clarity, particularly with newer top-level domains (TLDs). For example, www.example.miami is more clearly identifiable as a website than example.miami.

SEO Impact

Search engine rankings are unaffected by the inclusion or exclusion of "WWW," provided proper redirects are in place. Always use permanent (301) redirects when migrating between the two.

Supporting Both: A Costly Undertaking

While technically feasible, supporting both www.example.com and example.com simultaneously is generally impractical. It requires careful management of internal links (using relative URLs), analytics configuration, and deduplication of content in search engine results. To ensure Google treats both versions as the same, use canonical link tags <link href="https://www.example.com/my-article" rel="canonical"> on the preferred version (e.g., www.example.com).

Conclusion

Ultimately, both approaches are viable, each with its own trade-offs. The key is to choose a method, implement permanent redirects, and, if supporting both, manage the complexities carefully. The choice is largely a matter of preference and technical considerations.

The author supports the Open Internet/Free Speech Fund through the Write for Donation program.

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