The Inter UI font family


Inter UI started out in late 2016 as an experiment to build a perfectly pixel-fitting font at a specific small size (11px.) The idea was that by crafting a font in a particular way, with a particular coordinate system (Units Per EM), and for a particular target rasterization size (11), it would be possible to get the best of both sharpness and readability.

However after a few months of using an early version of Inter UI, it dawned on everyone exposed to the test that this approach had some serious real-world problems. Most notably that it was really hard to read longer text. Because of the pixel-aligning nature of that approach, the font took an almost mono-spaced appearance, making it really easy to read numbers, punctuation and very short words, but eye-straining to read anything longer.

The project was rebooted with a different approach, sticking with the specific UPM, but crafting glyphs and kerning in a way that made for more variation in the rhythm and smoother vertical and horizontal stems. As Inter UI was being developed, it was tested on an internal version of Figma—where the author of Inter UI works as a designer—and slowly improved upon based on experience and feedback.

FAQ

  • How do I enable and disable font features?
  • In web browsers you'll want to use font-feature-settings. In Figma you can access features via the Advanced Typography panel. In Illustrator, Photoshop and friends, you can access features via the Characters and OpenType panels. Sketch doesn't provide a UI for configuring font features, but there's a workaround using macOS's native font UI.
  • What is the difference between "unhinted" and "hinted" font files?
  • The font files in the "hinted" folders have additional data in them for assisting ClearType, the text rasterizer used by Microsoft Windows (and some Linux distributions.) You want to use the "hinted" fonts only if you are targeting Windows users and prefer the different look of these "hinted" fonts. Additionally, hinting data makes the font files larger, so if you are using Inter UI on websites, the extra size of these files is another consideration to make. This article explains hinting at a greater length.
  • How reliable are the fonts served from rsms.me/inter? Is it on a CDN?
  • rsms.me/inter is backed by GitHub's server network and distributed globally on the CloudFlare CDN, making usage of https://rsms.me/inter/inter-ui.css and associated font files very reliable and fast throughout the world.
  • Can I help with improving Inter UI?
  • Yes you can! Inter UI is an open-source project, meaning the source code—or "source design" if you will—that is used to build the font files are freely available to improve upon. Font making requires a fair bit of technical work and depending on what you'd like to do, some things might be more fun depending on your technical skills. The "Contributing" document is a great place to start. The document outlines where you can have the biggest impact, how things are setup and how to get started.
  • This website claims work started in 2016, but the git repository's log says it started later?
  • Inter UI was developed in an a private, internal git repository starting in November 2016, prior to being published on August 22, 2017. Between November 2016 and August 2017, there were 2 990 150 line edits made across 247 versions. The reason the public GitHub repository does not reflect this is the fact that the project was initially only internal at the company where the author works and had some sensitive information "checked in", like AWS server details and internal author identity in all commit messages. Maybe one day we can write an elaborate git filter-branch program and convert the filter the old repository to make it public, but what would be the point of that?  :—)
  • I've made a cool thing that uses Inter UI, can I share it with you?  or
  • I have a different question
  • Reach out on Twitter (@rsms) or over email