From what I read in the forum, I am supposed to put the event handler on the canvas, not the window. I tried that in a 1000 variations, did not work in FF and Edge. Same code works with window,self, body (via document.getElementById), but not with Canvas. Used the exact code found on stackoverslow, not working. After 6 hours of my lifetime trying to fix this bug, I am giving up. You know what? this iframe is my window handle. the parent page has no business to do in there. the iframe has it's own window handle, get your pranks off from it.