Since Cypress.io starts a browser to run the end-to-end tests, your Google Analytics tracking calls (also from other analytics services like plausible.io) are made, and you don't want to have wrong analytics.

Looking through cypress' documentation I finally found the blacklistHosts option that can be specified in your cypress.json configuration file.

Simply blacklist *.google-analytics.com by adding an entry to cypress.json like this:

{
  "blacklistHosts": "*.google-analytics.com",
  "video": false
}

But I want to specify more than one host to block

Simply specify blacklistHosts as an array, as the documentation says

By passing a string or array of strings you can block requests made to one or more hosts.

For example, to block calls to *.google-analytics.com and *.plausible.io, simply write:

{
  "blacklistHosts": ["*.google-analytics.com", "*.plausible.io"]
}