Huge difference Piwik pro vs GA4

Data collection and tags
1

My customer uses both analytics solutions, GA4 and Piwik Pro.
Before August, Piwik traffic was significantly higher than GA4, likely due to GDPR privacy compliance concerning Piwik. However, in August, GA4 now has for example 11.6% more visitors compared to Piwik. GA4 is also now collecting more visits and pageviews. I looked at the page level, and it affects all pages, so it can’t be a page-specific issue.
I also checked at the device category level (mobile, desktop, tablet), device type (iPhone 15, Samsung Galaxy S21…), and operating systems, and I didn’t find any values indicating an excessive amount of data collection at the GA4 level.

So I would like to know if you have any insights into what could have happened on Piwik’s side concerning data collection.

Best regards,
Arthur

2

Hi,

what I do not clearly understand: has the measured traffic in Piwik PRO taken a visible loss since that day or did numbers in GA4 just increase and Piwik PRO still reports the usual amount?

In other words: do you suspect Piwik PRO to collect too little data or has GA4 now more (maybe too much)?

In the second case I would try to find out if there were any changes in the GA4 set-up like an additional data stream, duplicate tagging or something like that.

best,
Markus

3

I’m curious on your implementation setup and how it can be related.

Are you using a tag manager to deploy both analytics tags?
Do any of the tags have precedence or have to wait, etc?

Best,

R