Variable Fonts

Variable fonts are one of the coolest innovations in web typography, and they’re now supported in all major browsers! They offer designers huge amounts of flexibility without bogging down pages with megabytes of font files.

Mozilla posted a brief intro to variable fonts at https://hacks.mozilla.org/2018/09/variable-fonts-arrive-in-firefox-62/, and you can see some in action at https://v-fonts.com/.