Cross sub-domain tracking not working with Firefox


Has anyone else here encountered issues with cross sub-domain tracking and Firefox?

We are using Universal Analytics and the cross domain tracking is working successfully on Chrome and IE. However, on Firefox, when the user moves from the subdomain to the domain, it registers as a new visit.

I’ve had trouble cross domain tracking in the past with Firefox, as their default set-up doesn’t allow sharing of cookies or something…

I was under the impression that this shouldn’t be a problem with cross sub-domain tracking though.


Hi Michael,

Are you tracking two domains that share a parent domain (ex. and or two completely different domains (ex. and

With the former, my understanding was that it should be automated with Universal Analytics on the Google side, so Firefox’s security settings shouldn’t affect it.

With the latter, I believe you need to add a few parameters to the codes on your respective domains, similar to here.


Thank you for coming back to me Quinn.

It’s scenario one: both domains share the parent domain. On further testing, it doesn’t work with Safari either.

My understanding is also that the security setting of the browsers shouldn’t affect it when they share the parent domain, but this is exactly the same problem I’ve had with cross domain tracking two different domains.

Would be interested to hear if anyone has got this working seamlessly on all browsers, or whether it is something to do with browser security settings.


Hi Michael,

I think we’re both under the impression that it should work as is, but one thing you could try is setting up GA as though the domains are completely separate, adding a self referral exclusion and also modifying your GA code a bit.

This article details both of those things. I’d try adding one at a time and testing after each.

I’ll also flag this and get Johnny, who’s our resident GA wiz to take a look at this–he’s home visiting family out of town, but he might have some further insight as well. He’ll be back on the office next Monday.


Thank you Quinn, if Johnny could possibly add some further insight when he’s back that would be much appreciated.

Will try both things you suggested too and see if I have any luck :slight_smile:

Thanks again



Hey Michael - This is the first i’ve heard of this issue but I’d be happy to dig into this together with you.

I’ll send you a email shortly with a few questions to better help narrow down the issue.