43in 4k monitor (Philips BDM4350UC). Not a particularly high dpi but LOTS of screen real estate, and not very expensive. You can have two documents open side by

43in 4k monitor (Philips BDM4350UC). Not a particularly high dpi but LOTS of screen real estate, and not very expensive. You can have two documents open side by side plus stackoverflow and the rendering of your website. But it requires 60Hz, because otherwise moving the mouse over such a large surface feels laggy and uncomfortable.