Hello everyone,
The WCAG contrast score (4.5:1 ratio) is an essential standard for accessibility, but it only addresses one aspect of the problem: color. Yet, text readability also depends on its form—a criterion currently not measured in a standardized way.
Concrete example: A Times New Roman 12px text with a perfect contrast (7:1) can be less readable than Verdana 14px (5:1 contrast), simply due to its lower x-height or tight serifs. Other factors like glyph complexity, line spacing, or relative size play a key role but are not evaluated by current tools.
A Proposal: A Global Readability Score
Why not imagine an indicator that would integrate:
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20%: X-height (e.g., 51% for Inter vs. 45% for Times)
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15%: Glyph complexity (number of points in a ‘g’ or ‘a’)
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15%: Weight and internal contrast (stroke thickness)
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20%: Color contrast (WCAG)
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15%: Size and line spacing
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10%: Display resolution
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5%: Letter spacing
Result: A score out of 100, similar to Lighthouse. Examples:
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Inter Regular 16px → 92/100 (excellent readability)
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Times New Roman 12px → 68/100 (needs improvement)
Why Discuss This?
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To designers: Which criteria should be adjusted? Should font family (serif vs. sans-serif) or character width be included?
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To developers: Would a tool (browser extension, Figma plugin) to calculate this score be useful? What format would work best?
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To the community: Are you aware of existing work on this topic? What criteria do you think are missing?
Useful Resources:
If this topic interests you, share your ideas, critiques, or resources! The goal is to explore the feasibility of such a score. 