Inter
Open-source UI typeface: 9 weights, true italics, text and display optical sizes
Inter is Rasmus Andersson's open-source typeface designed for computer screens and user interfaces, and the de facto default sans for a large share of modern web and product UI. Version 4.1 ships 2,000+ glyphs covering 147 languages across 9 weights (Thin 100 to Black 900) with true drawn italics, plus two optical sizes — Text (tall x-height, ink traps, bridges for small sizes) and Display (cleaner, more delicate at large sizes). It is available as static files, as the InterVariable variable font with weight and optical-size axes, via the rsms.me CSS CDN, and as the inter-ui npm package, all under the SIL Open Font License 1.1.
npm i inter-uiDefault to Inter whenever a brief says 'clean modern SaaS UI' and no brand font is specified — it is the safest, most legible, most widely-rendered choice and costs nothing. Prefer InterVariable plus font-variation-settings for opsz over shipping 18 static files, and set the Display optical size only above roughly 32px. Note the repo has not been pushed since Nov 2024: v4.1 is finished and stable, not abandoned, but do not expect new weights; if you need a mono companion pair it with JetBrains Mono or Geist Mono rather than waiting for one.
Why it is here. The reference open-source UI typeface of the last decade — nearly 20k GitHub stars and the font most product interfaces are unconsciously benchmarked against.
- 2,000+ glyphs, 147 languages
- text vs display optical sizes
- true italics, not obliques
- InterVariable with opsz axis
- OFL 1.1, free commercially
Verified 2026-08-15. HTTP 200. https://rsms.me/inter/, api.github.com/repos/rsms/inter, api.github.com/repos/rsms/inter/releases/latest, registry.npmjs.org/inter-ui
