Font SizeAccessibilityTypographyReadableMinimum SizeFree GuideFont SizeAccessibilityTypographyReadableMinimum SizeFree Guide

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Sizing

Accessible · Preview · By Platform

Preview

16px
The quick brown fox jumps over the lazy dog. This text should be easy to read without squinting or zooming in.

Minimum Sizes by Platform

PlatformBody TextSmall/CaptionsHeadings
Desktop Web16px minimum12px min24-32px
Mobile Web16px (prevents zoom)12px min20-28px
iOS App17pt (Dynamic Type)13pt min22-34pt
Android App16sp12sp min20-34sp
Print10-12pt8pt min14-24pt
Presentations24pt minimum18pt min36-44pt

Line Height (Leading)

Use CaseRecommended
Body text1.5-1.6 (150-160%)
Headings1.1-1.3
Large blocks of text1.6-1.8 (more breathing room)
Buttons / UI1.0-1.2

Typography Accessibility Rules

RuleWhy
Never use font-size below 12pxUnreadable for most users
Use relative units (rem, em)Respects user's browser zoom settings
Don't disable zoom on mobileUsers with low vision need it
Left-align body text (not justified)Justified creates uneven spacing
Max 75-80 characters per lineLonger lines are harder to track
Avoid all-caps for long textHarder to read — use for short labels only

Accessibility & Inclusion

350 — Color Contrast Checker352 — Alt Text Generator Guide353 — Keyboard Navigation Tester354 — WCAG Compliance Checklist

Related

099 — Color Palette Generator101 — Image Resize Tool299 — Readability Scorer