Unifying our mobile and desktop domains

Summary

How we achieved 20% faster mobile response times, improved SEO, and reduced infrastructure load. How we achieved 20% faster mobile response times, improved SEO, and reduced infrastructure load. Until now, when you visited a wiki (like en.wikipedia.org), the server responded in one of two ways: a desktop page, or a redirect to the equivalent mobile URL (like en.m.wikipedia.org). This mobile URL in turn served the mobile version of the page from MediaWiki. Our servers have operated this way since 2011, when we deployed MobileFrontend. Diagram of technical change. Over the past two months we unified the mobile and desktop domain for all wikis (timeline). This means we no longer redirect mobile users to a separate domain while the page is loading. We completed the change on Wednesday 8 October after deploying to English Wikipedia. The mobile domains became dormant within 24 hours, which confirms that most mobile traffic arrived on Wikipedia via the standard domains and thus experienced a redirect until now.[1][2] Why? Why did we have a separate mobile domain? And, why did we believe that changing this might benefit us? The year is 2008 and all sorts of websites large and small have a mobile subdomain. The BBC, IMDb, Facebook, and newspapers around the world all featured the iconic m-dot domain. For Wikipedia, a separate mobile domain made the mobile experiment low-risk to launch and avoided technical limitations. It became the default in 2011 by way of a redirect. Fast-forward seventeen years, and much has changed. It is no longer common for websites to have m-dot domains. Wikipedia’s use of it is surprising to our present day audience, and it may decrease the perceived strength of domain branding. The technical limitations we had in 2008 have long been solved, with the Wikimedia CDN having efficient and well-tested support for variable responses under a single URL. And above all, we had reason to believe Google stopped supporting separate mobile domains, which motivate...