Building Accessible Web Applications: A Practical Developer's Guide

Web accessibility ensures your application works for everyone, including the 1.3 billion people worldwide living with disabilities. Beyond being the right thing to do, it improves SEO, expands your audience, and is legally required in many jurisdictions.

Semantic HTML Is the Foundation

Use proper HTML elements: <nav> for navigation, <main> for primary content, <button> for actions (not <div onclick>), and <a> for links. Screen readers use these elements to help users navigate your page efficiently. A <div> with a click handler is invisible to assistive technology.

Keyboard Navigation

Every interactive element must be reachable and operable via keyboard. Test by pressing Tab through your entire page. Can you reach every button, link, and form field? Can you activate them with Enter or Space? Can you close modals with Escape? If not, fix the tab order and add keyboard event handlers.

ARIA Attributes When HTML Isn't Enough

ARIA fills gaps where semantic HTML falls short. Use aria-label for icon-only buttons: <button aria-label="Close menu">. Use aria-live="polite" for dynamic content that should be announced by screen readers. Use role="alert" for error messages. The first rule of ARIA: don't use ARIA if native HTML can do the job.

Color Contrast and Visual Design

Text must have a contrast ratio of at least 4.5:1 against its background (3:1 for large text). Never use color as the only way to convey information — always pair it with icons, text, or patterns. Use browser DevTools' accessibility inspector to check contrast ratios quickly.

Testing with Real Assistive Technology

Automated tools like Lighthouse and axe catch about 30% of accessibility issues. For real confidence, test with a screen reader: VoiceOver on Mac, NVDA on Windows (free), or TalkBack on Android. Navigate your app with your eyes closed — you'll find issues no automated tool catches.

Start with these fundamentals and incrementally improve. Every accessibility fix makes your app better for all users, not just those with disabilities.