Open Sans
Google Fonts · Steve Matteson · 2010

One of the most widely deployed typefaces on the web, Open Sans delivers dependable legibility across sizes and languages.
About
Designed by Steve Matteson and released through Google, Open Sans was built specifically for screen clarity and broad language compatibility, covering Latin, Cyrillic, and Greek scripts. Its open letterforms and generous x-height make it reliable at body sizes in interfaces, articles, and documents alike. While its ubiquity has reduced its distinctiveness, it remains a solid, dependable workhorse.
Classification
A highly legible humanist sans with open apertures, friendly proportions, and extensive language support. Designed with screen rendering in mind, it balances neutrality with warmth.