Google's user-level identification changes


We use Matomo web tracking on our clients websites - we are interested in referrer/campaign tracking at an individual level for attribution purposes (via userid or by ecommerce order id for known individuals or matomo visitor id for anonymous browsers). We have recently been asked by clients and prospective clients about the upcoming changes made by google. We have responded that we are only tracking 1st party data which has been consented - however the recent update by google has suggested that it won’t support any user-level tracking - can anyone provide any information on this? A matomo visitor id is a user level identifier, will this continue to be supported after Google’s changes? It would be helpful if Matomo issued an official response (like many other companies are doing) so that we can reassure our clients or be prepared to make changes.

Here is the official statement from google and an article that attempts to explain the changes. I look forward to receiving some advice on this matter.


I am not entirely sure what these changes Google is doing has to do with you tracking userIDs on your website).

I have lost a bit the overview over what Google is planning as it seems to be a lot of vague changes hidden behind a lot of marketing and trying to sound privacy-friendly.

But it seems to boild down to the idea of making cookies far less useful (e.g. by restricting how they can be accessed between domains) and replacing them with their own solutions like FLoc (which has its own huge flaws).

But all of this has little to do with your shop if you are using userid to uniquely identify users. (and I think most of these Google ideas are more ideas than already finished implementations)
What’s more important is that you pay attention to the privacy laws of your customers and make sure that you follow them strictly (especially if you are uniquely identifying them via userid).

One thing that Google did, that affects you is Referrers: Google Chrome (and Safari and Firefox) have changed the default referrer policy so that if someone visits you website from another website (and the other site doesn’t set a referrer policy) then the browser tells your site only the domain of the other site, not the full URL. (see e.g. for more information)

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Hi Lukas

I appreciate you taking the time to respond. I am also a little confused and would like to respond to our customers with confidence that it won’t affect them.

In the Google statement the last paragraph states the following…

Keeping the internet open and accessible for everyone requires all of us to do more to protect privacy — and that means an end to not only third-party cookies, but also any technology used for tracking individual people as they browse the web

Which to me sounds like they are planning to take action with technology like Matomo? I’m not sure if that’s possible or not but was hoping to find an official response from Matomo like other services are doing e.g.

This way we can direct any concerned customers to your statement?

Thanks again!

Thanks for your message. If i understand correctly your message, because Matomo uses 1st party cookies, and because changes by browsers only affect 3rd party (for example advertising) cookies, then Matomo tracking is not affected​​ by these changes.

Matomo would only be affected if you used the 3rd party cookie tracking (by default it is not used and almost nobody would use this feature)