How to use readable text sizes and contrast for clarity

When body text is too small or uses low contrast against its background, users stop engaging with the content. They may skim the headings, scroll past the paragraphs, or leave the page entirely. A wall of small, light-gray text on white doesn’t just look hard to read — it signals that the content isn’t worth the effort.

The fix is to use text sizes and contrast ratios that make reading effortless. Body text should be large enough to read without zooming — typically 16px minimum on mobile, 18px+ on desktop. Color contrast between text and background should meet at least the WCAG AA standard (4.5:1 for body text), which ensures legibility across different screens, lighting conditions, and visual abilities.

Audit your body text on a real device — what looks fine on a design tool at 200% zoom may be unreadable at actual size. Increase line height (1.5–1.75× the font size) so lines don’t feel cramped. Avoid light gray text on white backgrounds — the aesthetic may feel “clean” but the readability cost is real. Test in bright sunlight if your audience uses mobile outdoors.

• Set body text to at least 16px on mobile and 18px+ on desktop for comfortable reading.
• Maintain a contrast ratio of at least 4.5:1 between text color and background color (WCAG AA).
• Use generous line height (1.5–1.75×) to keep lines from feeling cramped or overlapping.
• Avoid light gray body text on white — it reduces readability even if it looks aesthetically minimal.
• Test on real devices in real lighting to confirm text is legible without zooming.

Readable text is the baseline for everything else on a page. Users who can scan and absorb content effortlessly are more likely to engage with the offer, trust the product, and take action — because they actually read what you wrote.