A website should not be able to alter the browser interface. Is the change just in popup windows? You can prevent those with dom... settings in about:config. dom.disable_window_open_feature.location -> true (address) dom.disable_window_open_feature.menubar -> true (menu bar) dom.disable_window_open_feature.personalbar -> true (bookmarks bar) dom.disable_window_open_feature.scrollbars -> true dom.disable_window_open_feature.titlebar -> true dom.disable_window_open_feature.toolbar -> true (navigation bar)

jakartax said

There's a website that I need to visit for work related reasons. Unfortunately the site removes my Firefox favorites toolbar and my menu bar (File, Edit, View, etc...). Is there a way to prevent this website from altering my browser like this?

finitarry,

You are correct, this happens when getting pop-up windows from the site. Problem solved, I made the changes you recommended and everything is working as expected! Many thanks!