Why Do Some Sites Start with WWW2?

“WWW” is a sequence of letters we’re pretty comfortable seeing in front of a domain name, even if we’re not exactly sure why it’s there. Every now and then, though, you might have noticed a few numbers sneaking onto the end – WWW1, WWW2, maybe even WWW3. Have you stumbled onto a parallel version of the Internet? Are you being phished?

While you should always watch out for weird site-name changes, in this case you don’t need to worry. The number probably just means the site you’re browsing is using a slightly old-school load-balancing technique. You’re still on the same site, but your traffic is being directed to a particular server because the others are busy.

Why do some sites seem to need WWW[number]?

Even though it’s an unnecessary naming convention, some sites, especially larger and older ones, use the WWW[number] format as a way to name subdomains (separate sections of the same site, but not necessarily on separate machines) or as hostnames for different physical servers. In the latter case, this is probably a load-balancing technique. Each server can only handle so many users, so when you visit a site by typing in the address, with or without the WWW, your request might hit a load balancer that checks the status of each server and decides to route your traffic towards, say, the WWW3 subdomain.

It might also mean that their main server is having trouble, and you’re being sent to a backup, or it could mean that there’s some sort of a test or update going on, or maybe they’ve just decided WWW3 is the way to go. Either way, you’re essentially visiting the same site, even though if you try to get back to www3.example.com later, the load balancer might bounce you back to the main www.example.com site.

So no worries then?

It’s hard to tell what’s going on behind the scenes by just glancing at the WWW prefix, but as long as the domain name is the same, you don’t typically need to be concerned about alternative hostnames or subdomains. You probably won’t see very many sites using this anymore, since there are more sophisticated load-balancing techniques now available that mostly work behind the scenes, but there’s nothing inherently insecure about adding numbers to your WWW, and if a site has been working well with this method, they just might not see the point in changing it. Indeed, it often pops up on banking websites, which use different subdomains for security and may have named them with the WWW convention.