Hyperlegible Sans: a free, open-source font for accessible design

"Capital I I added subtle top and bottom bars. This keeps it visually aligned with Inter's geometry while removing its similarity to lowercase l and numeral 1. Low-vision readers rely on disambiguation, and this single change dramatically improves clarity without altering the overall feel. Lowercase l I added a small baseline spur. This makes it unmistakable as a lowercase letter and prevents confusion with 1. It also provides more visual stability inside dense UI strings."

"Zero I added a slash. A slashed zero is simply more readable for everyone. It avoids the O/0 problem entirely, especially in interfaces that rely heavily on numeric input or one-time codes. Capital O I widened it slightly. Inter's O is balanced and elegant, but too close to the zero for accessibility-first interfaces. A slightly wider form keeps its beauty while improving distinction."

"a and e I opened both apertures. The two-storey a and the e's crossbar were always a bit tight for low-vision readers. Opening these shapes makes them more readable at small sizes and more resistant to blur. The Number 8 I adjusted the structure of the numeral 8 by reducing the symmetry and tightening the relationship between its upper and lower bowls. In Inter, the 8 is balanced and elegant, but at small sizes or under blur it can collapse into a dense, indistinct shape."

Subtle glyph modifications improve character distinction for low-vision readers while maintaining Inter's aesthetic. Capital I gains top and bottom bars to separate it from lowercase l and numeral 1. Lowercase l receives a baseline spur for stability in dense UI strings. Zero is slashed and Capital O slightly widened to prevent O/0 confusion. Apertures on a and e are opened to aid readability at small sizes. The numeral 8's bowls are adjusted to reduce symmetry and prevent collapse under blur. Kerning and spacing are increased for commonly collapsing pairs to enhance hyperlegibility without compromising beauty. Accessibility should not sacrifice aesthetics.

Read at Medium