[fiddlerwoaroof]

Yeah, making incognito mode detectable would be a huge privacy issue: it would enable blocking users based on incognito and all sorts of other bad issues.

If incognito mode is undetectable, there’s no way for Google Analytics to distinguish between “cross-device” traffic from an incognito window vs. from a phone and a laptop. Whether or not cross-decide tracking is good or bad, it’s irrelevant to this question.

[postalrat]

How is blocking incognito a bad thing? Right there it should tell the user they need to avoid that site at any price.

I'm pretty sure incognito is detectable right now. I'm always going to assume it is.