To www or not to www – update

I had posted earlier about whether it was better to use www or not to use www as a prefix to your domain. My conclusion back then was to go without www as I have done on my website. However, I have been reading more about performance improvements for websites and recently came across this nugget from Yahoo (which has some excellent documentation with regards to optimal performance – that ties to their YSlow extension for Firefox).

Another benefit of hosting static components on a cookie-free domain is that some proxies might refuse to cache the components that are requested with cookies. On a related note, if you wonder if you should use or for your home page, consider the cookie impact. Omitting www leaves you no choice but to write cookies to *, so for performance reasons it’s best to use the www subdomain and write the cookies to that subdomain.


I have often wanted to use a static sub-domain for our client sites (to increase the number of parallel requests) but the addition of having it be a cookie-less domain seems even more appealing and as the quote above describes – it is probably better to go with a www domain to avoid having a static subdomain pass cookies – if you have a large site. If you have a smaller site, you can still safely go without “www” as is the case with my site. But if your site ever grows, it could be a problem.