Intro I use several three-monitor setups and one of the setups has a large TV-size screen as the monitor. I typically put my browser instances over there and need to shrink them to a more zoomed-out level to make websites usable at that size. The answer was to change the layout.css.devPixelsPerPx in the about:config1. I changed mine to 0.8, which was equal to about the 80% zoom level which works for me.