Inter is a single sans-serif family by Rasmus Andersson, built specifically for screen interfaces - over 2,000 glyphs, support for 147 languages, and weights from Thin to Black.
It was designed around UI legibility specifically, not adapted from a print typeface, which shows in how it holds up at small sizes on screens.
A strong default for product and interface design where legibility at 12 to 14px matters more than typographic personality.
Released under the SIL Open Font License 1.1 - fully free for personal and commercial use, no restrictions, no attribution required.
A free typeface designed specifically for high legibility in user interfaces.