Use semantic HTML with proper headings and structural elements to enable assistive technologies to interpret page content correctly. 2. Ensure keyboard accessibility by making all interactive elements focusable, providing visible focus indicators, managing focus in dynamic components, and supporting logical navigation. 3. Provide text alternatives such as alt text for images and proper labels for form controls using label elements or ARIA attributes, and associate error messages with aria-describedby. 4. Design with sufficient color contrast (at least 4.5:1 for normal text) and avoid conveying information through color alone by supplementing with icons or text. 5. Make dynamic content accessible by using ARIA live regions to announce updates, properly managing roles and states, and avoiding excessive announcements. 6. Build accessible custom components by applying appropriate ARIA roles, managing keyboard interaction and focus, and testing with screen readers. 7. Test accessibility using automated tools like Axe and Lighthouse, manual keyboard and screen reader testing, and involving users with disabilities to uncover real-world issues. Accessibility is an ongoing process that ensures web applications are perceivable, operable, and understandable for everyone, including those using keyboards or screen readers.

Creating accessible web applications isn’t just a technical requirement — it’s a fundamental part of building inclusive digital experiences. Accessibility (often abbreviated as A11Y, where “11” stands for the 11 letters between “A” and “Y”) ensures that people with disabilities can perceive, understand, navigate, and interact with the web. Here are key best practices to follow when building accessible web applications.

1. Use Semantic HTML

Semantic HTML is the foundation of accessibility. It gives meaning to content and helps assistive technologies (like screen readers) interpret the structure of your page.

• Use proper heading hierarchy (<h1></h1> to <h6></h6>) to organize content logically.
• Use <nav></nav>, <main></main>, <section></section>, <article></article>, <aside></aside>, and <footer></footer> to define page regions.
• Use <button></button> for buttons, <a></a> for links, and avoid using <div> or <code><span></span> for interactive elements.

  Why it matters: Screen readers rely on semantic tags to navigate. A

  won’t be announced as a button, but a <button></button> will.

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  2. Ensure Keyboard Accessibility

  Many users navigate the web using only a keyboard (e.g., people with motor impairments or screen reader users). Your app must be fully operable without a mouse.

  • Ensure all interactive elements are reachable via Tab.
  • Provide visible focus indicators (don’t remove outline without replacing it).
  • Manage focus programmatically when needed (e.g., after opening a modal).
  • Support logical tab order and avoid trapping focus.

  Common pitfalls:

  • Modals that don’t trap focus
  • Dropdowns that can’t be closed with Escape
  • Custom widgets without keyboard support

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  3. Provide Text Alternatives and Labels

  Non-text content must have accessible alternatives.

  • Use alt attributes for meaningful images: <img src="/static/imghw/default1.png" data-src="chart.png" class="lazy" alt="Sales increased 20% in Q2">
  • Use empty alt="" for decorative images.
  • Label form controls using <label for="id"></label> or aria-labelledby.
  • Use aria-label or aria-labelledby when a visible label isn’t present.

  Example:

  <label for="search">Search</label>
  <input type="text" id="search" aria-label="Search the site">

  Also, ensure error messages are programmatically associated using aria-describedby.

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  4. Design with Sufficient Color Contrast and Visual Clarity

  Color alone should never convey critical information.

  • Maintain a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text (WCAG AA standard).
  • Test your designs with tools like WebAIM’s Contrast Checker.
  • Use icons, text, or patterns in addition to color (e.g., red error text an error icon).

  Also, ensure your UI is responsive and usable at different zoom levels (up to 200–400%).

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  5. Make Dynamic Content Accessible

  Modern web apps often update content dynamically (e.g., AJAX, React state changes). These changes must be communicated to assistive technologies.

  • Use ARIA live regions (aria-live) for important updates:

    <div aria-live="polite">Item added to cart</div>

  • Update landmarks and roles when content changes.
  • Notify users of status changes (e.g., loading states, form submission results).

  Avoid overusing aria-live — too many announcements can overwhelm users.

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  6. Build Accessible Custom Components

  When creating custom UI components (e.g., dropdowns, tabs, modals), you must manually implement accessibility.

  For a custom dropdown:

  • Use role="button" and aria-haspopup="true"
  • Manage focus and keyboard interaction (ArrowDown, Enter, Escape)
  • Use aria-expanded to indicate open/closed state
  • Ensure the list has role="listbox" and options have role="option"

  For tabs:

  • Use role="tablist", role="tab", and role="tabpanel"
  • Manage aria-selected and tabindex appropriately
  • Support keyboard navigation (Left/Right arrows)

  Always test with real screen readers (e.g., NVDA, VoiceOver, JAWS).

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  7. Test with Real Users and Tools

  Automated tools catch only about 30–50% of accessibility issues.

  Use a combination of:

  • Automated checkers: Axe, Lighthouse, WAVE
  • Manual keyboard testing
  • Screen reader testing (VoiceOver on macOS, NVDA on Windows)
  • Involving users with disabilities in usability testing

  Don’t rely solely on automated tools — real-world usage reveals the most critical issues.

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  Accessibility is an ongoing process, not a one-time checklist. By integrating these practices into your development workflow — from design to deployment — you ensure your web applications are usable by everyone, regardless of ability.

  Basically, if it’s usable by someone using only a keyboard or a screen reader, you’re on the right track.