but how do I test if the ip is indeed anonimysed
Use Chrome

Install the Google Analytics Debugger extension
https://chrome.google.com/webstore/d...hjechhna?hl=en

Go to your website

Check the requests sent to Google Analytics, they should have the &aip parameter set to aip=1


but what if the user wants to re enable Google Analytics back
He has to delete the Opt-Out Cookie

Use Firefox Version 60 and above

Go to your website

Click on Site Information > Website Security > more info > show cookies
If the GA Opt-Out Cookie is set you will see:
ga-disable-UA-12345678-9
If you delete this cookie GA is "enabled" again