Check whether a window is Popup or not?

Question

This question is not the duplicate of if window is popup , But a similar one.

I am developing a extension which injects scripts to all web pages. I need to detect whether the window is popup or not.

Note: I am not the one who is opening the popup window, So the above solution won't work.

Answer 1

I've found that some browsers will set window.opener to window in certain cases. This is the most reliable popup check that I am using right now.

if (window.opener && window.opener !== window) {   // you are in a popup }