Contrast and Readability: Best Practices

Estimated duration: 5 minutes

Learning objectives:

After completing this reading, you will be able to:

Introduction

When it comes to creating outstanding user experiences, contrast and readability are two of the most critical yet often overlooked pillars of UI design. As a UI/UX developer, your design isn't successful just because it looks beautiful. It's successful when users can easily read, understand, and interact with the content without strain. Good contrast and readability directly impact accessibility, user engagement, trust, and even conversion rates.

Let's explore why they matter and how to get them right, with real-world examples.

1. Why contrast and readability matter

Poor contrast and difficult-to-read text led to:

In short, even the most powerful message fails if users can't comfortably read it.

2. Key best practices for contrast and readability

(a) Maintain sufficient color contrast

Ensure there is a strong difference between text and background colors. The WCAG (Web Content Accessibility Guidelines) recommends:

Real-world example

Apple's website uses stark black text on a white background for product descriptions, ensuring effortless readability across all devices.

Developer tip

Use tools like WebAIM Contrast Checker or browser extensions to test color contrast ratios during development.

(b) Choose fonts wisely

Use clean, legible fonts that work well at different screen sizes. Avoid overly decorative fonts for body text.

Real-world example

Medium.com uses a simple, high-contrast serif font for its articles, optimized for long-form reading across mobile and desktop.

Developer tip

Stick to 2–3 font families max. Ensure the primary body text uses fonts built for readability, like Roboto, Open Sans, Georgia, or Inter.

(c) Set adequate font size and line spacing

Real-world example

In a redesign, LinkedIn's mobile app increased font sizes and improved line spacing, making job descriptions and messages far easier to read on small screens.

Developer tip

Always test text on smaller viewports — what looks good on a large monitor might feel cramped on mobile.

(d) Avoid using color alone to convey information

Don't rely solely on color differences to indicate important information like errors, status, or links. Use icons, labels, underlines, or different textures along with color.

Real-world example

Google Forms shows a red outline and a warning message for unfilled required fields, which is not just a color change but also helps color-blind users understand errors.

Developer tip

Always design for color blindness and vision deficiencies. Tools such as Color Oracle can simulate different vision conditions.

(e) Provide dark mode and light mode options

Give users the choice of themes. Some prefer dark backgrounds for less eye strain, especially in low-light environments.

Real-world example

Twitter and YouTube both allow users to toggle between light and dark modes, improving comfort for different usage scenarios.

Developer tip

In dark mode, ensure enough contrast by using off-white text (#E0E0E0 instead of pure white) and avoid true-black backgrounds, which create harsh light gaps.

3. Mistakes to avoid

4. Developer tools to ensure good contrast and readability

Summary

For UI/UX developers, contrast and readability are non-negotiable essentials. When users can effortlessly read your text and distinguish your elements, they stay longer, interact more confidently, and leave with a positive impression.

Remember:

"Good design isn't just about what users see — it's about what users can read and understand without effort."

Design with contrast in mind. Develop with readability at heart. That's how you create experiences that truly connect.