Research
Readability Research
Research behind web typography best practices: line length studies, WCAG contrast standards, saccade and eye-tracking findings, and typographic defaults used in Grade.
Grade recommendations are derived from typographic research, accessibility standards, and testing on real interfaces — not opinion. This page summarizes the research domains behind each lesson variable.
Line length and measure
Studies on reading speed and comprehension consistently find optimal line lengths between 45 and 75 characters. Bringhurst, Tinker, and later web-focused research align on this range. Long lines increase return-saccade errors; short lines break rhythm.
Contrast and WCAG
WCAG 2.x defines contrast ratio using relative luminance. The 4.5:1 AA threshold for normal text is based on readability for low-vision users across displays and lighting conditions. Grade's contrast lesson uses the same formula.
Hierarchy and preattentive processing
Visual hierarchy research shows size differences above roughly 2:1 register preattentively — before conscious reading. Below that threshold, readers must compare elements attentively to determine rank.
Line height and saccade accuracy
Tight leading increases line-transition errors in multiline text. Comfortable line height (1.5–1.65 for body) reduces cognitive load and supports vertical rhythm across paragraphs.
Interactive lessons
Related guides
Glossary
Frequently asked questions
- Does Grade cite primary research papers?
- Grade synthesizes established typographic practice and WCAG standards into practical CSS defaults. The web typography resources page links to primary WCAG documentation and further reading.
- Are Grade defaults universal for every brand?
- Defaults are starting points tested on real interfaces. Brand typefaces, dense dashboards, and accessibility requirements may need adjustment — but the underlying variables still apply.