Note: We’re talking about readability from a design standpoint in this article, not in terms of understanding the content itself (which is covered in WCAG 3.1: Readable).
Why readable text matters
Poor readability can exclude users with visual impairments, cognitive disabilities, or those in various viewing conditions.
- Inclusivity – Users with low vision, color blindness, or aging eyesight need clear text to navigate content.
- Cognitive accessibility – Simple fonts and high contrast make it easier for users with dyslexia, ADHD, and similar challenges to process information.
- User experience – Readable text benefits everyone, especially on small screens, in low-light conditions, or when users are in a hurry.
Best practices for ensuring readable text
Choose legible fonts
Font choice significantly impacts readability.
- Use sans-serif fonts for body text – Fonts like Arial, Helvetica, and Roboto are generally easier to read on screens.
- Limit decorative fonts – Reserve decorative or script fonts for headings, and keep them brief.
- Set a minimum font size of 16px – This ensures readability across devices; increase font size for headings to establish hierarchy.
Maintain high color contrast
Color contrast is essential for readability, especially for visually impaired users.
- Follow WCAG guidelines – Aim for a 4.5:1 contrast ratio for body text and 3:1 for large text (see WCAG 1.4.3 Contrast).
- Avoid hard-to-see color pairs – Skip combinations like light gray on white or red on green. Use tools like WebAIM’s Contrast Checker to test your choices.
Pay attention to line spacing and text alignment
Spacing and alignment affect readability.
- Set line height to at least 1.5 times the font size – This helps reduce eye strain and makes text easier to follow.
- Left-align text – Avoid justified text, which can create uneven word spacing. Use left alignment for a consistent reading flow.
- Break up long paragraphs – Shorter paragraphs improve readability and make information easier to digest.
Provide sufficient white space
White space around text improves focus and readability.
- Space out elements – Ensure there’s enough space around text, images, and other content. White space prevents a crowded look and enhances focus.
- Use margins and padding – This helps separate content and makes it more scannable.
Don’t rely solely on color
Color should not be the only way to convey information.
- Add text labels or icons – If color indicates meaning, pair it with a label or icon for clarity.
- Test for color blindness – Use Silktide’s Color Blindness Simulator to ensure your design is accessible to users with color vision deficiencies.
Support text scaling
Allow users to adjust text size without sacrificing readability.
- Use responsive design – Let text resize and reflow on different screens and devices.
- Use relative units (em or rem) – This enables text to scale according to user preferences and device settings.
Test for readability
Testing ensures your text is readable for everyone.
- Test with diverse users – Involve users with disabilities to gain insights into real-world readability.
- Use accessibility tools – Tools like Silktide’s Accessibility Checker can help identify readability issues.
- Check screen reader compatibility – Ensure text is accessible for users who rely on assistive technologies.