Trying to make the Subdomain work as a Cookieless Domain

Question

A subdomain is not setting to Cookieless Domain

I have a website to which am trying to serve all the images/css/js through a cookieless subdomain setup.

So for this abc.com website, I made a subdomain - "static" and set it to redirect properly to the page assets. But after checking on various tools, such as Gtmetrix or Pingdom, they still showing it's not cookie-free domain.

I am stuck on what to do next that where I am wrong. Or I will need something to make the subdomain cookieless?

Answer 1

I know it is a four month old question, but have been working on this and what I have learned might help you or another down the road.

Setting up static.abc.com can work if your main site is www.abc.com and NOT simply abc.com. The www makes all the difference.

If your main site has www then setting your cookie's Domain to www.abc.com will share your cookies with all subdomains of www.abc.com. This will NOT include static.abc.com - static will not be considered a subdomain of www. So calls to files using static.abc.com will be cookieless. You will (probably) want to set your cookie's Path for www.abc.com to "/" to allow sharing of cookies for all directories under www.abc.com.

However if your main site doesn't have the www in the domain (a non-www or naked domain), static.abc.com is now a subdomain of it and they will share cookies. If this is the case, the only solution is to purchase another domain.

I have a www domain and I was having the same problem as you - the cookies were being passed with every file on static.mysite.com. My issue was that I had the Domain parameter of setcookie without the www and so the cookies were sharing with all subdomains of mysite.com (which included www and static). Once I added the www, the cookies stopped being sent with static (verified with GTMetrix).

Hope this makes sense.