UI & UX · 6 min read

How to Test Font Readability and Legibility Across Screens

Scientific methods for evaluating reading speed, saccadic eye movements, contrast ratios, and visual fatigue.

Legibility vs. Readability

- **Legibility:** How easily one letterform can be distinguished from another (micro-level anatomy).
- **Readability:** How easily words, sentences, and paragraphs flow together during sustained reading (macro-level spacing, measure, and leading).

Frequently Asked Questions

What is the optimal line length (measure) for web reading?
Between 45 and 75 characters per line (including spaces), with 65 characters considered the gold standard for comfortable reading on desktop screens.