Officially Tara 🕷️ 
🌹i just got the best pop up I've ever received on a website, on @stefan 's website
lars@tarajdactyl @stefan Shouldn't a good adblocker be transparent and therefore undetectable for the website?
Григорий Клюшниковlars, it's kinda impossible to build an undetectable ad blocker. If an ad fails to load, this affects the page layout, and that can be detected from JS by checking the sizes of the elements and/or traversing the DOM tree. Also onload/onerror events for ad-related scripts. Also the absence of global variables these scripts define. And simplest of them all — just try to load a URL that has ad-related words in it and see whether the request fails.
@grishka @tarajdactyl I guess as an #AdBlocker developer I'd create a shadow DOM tree that behaves exactly the same as in a non-blocking browser but runs in a sandboxed environment and is never shown to the user. You then can selectively copy elements to the real DOM tree that is actually displayed and compress the layout if possible.