Just for font rendering you need harfbuzz+freetype if you want something decent (e.g not stb_truetype) so you're already talking 5-8 mb of libraries at the bare minimum. You also want ICU for proper unicode processing unless you don't have any unicode string operation anywhere in your software . +16 mb and we haven't rendered a single pixel. Then you're making a GUI - you aren't going to restrict it to people with a GeForce RTX1070+ right ? No, you want everyone to be able to use it, yes, including that one person in the back with a GMA500 intel chipset which does not support opengl 3.2 but will leave an absolutely scathing review of your app if it does not work on their machine (alternative: same thing but it's the company you're building the software for which had a fleet of 2008 dell Inspiron for their employees). So now you need to ship ANGLE + some software opengl implementation so that people with 2008 eeePCs won't see a black square when they open your app. Add 10 or so more megabytes and you have the very, very, very bare minimum on which to start building your UI toolkit if you want to cover common use cases.