MacOS has some peculiarity where it reports a window’s framebuffer has half the width and height that it really has. Check for example this issue in GLFW MacOS framebuffer size and window content scale incorrect on external display without high dpi · Issue #1857 · glfw/glfw · GitHub, one needs to adjust for that and GLFW seems to have some related flags. I wanted to look into this as well to understand how to make GLMakie look better on Macs, currently it’s just really small because it uses the retina pixels as if they were normal pixels.