Web Fundamentals: Accessibility and Performance

Site Admin · 11 Sep 2026 · 6 views

Why These Matter

Accessibility means everyone can use your site, including people relying on screen readers, keyboards, or voice control. Performance means the site loads and responds quickly. They are not optional extras: accessible, fast sites rank better in search results and serve a far wider audience.

Accessibility Fundamentals

Start with structure and semantics, which also help performance in subtle ways.

Use one h1 per page and a logical heading order.
Give every image a meaningful alt attribute.
Use real buttons for clickable actions, not styled divs.
Keep color contrast ratio above the WCAG guidance.
Make sure every interactive element works with the Tab key.

<img src="diagram.png" alt="Flow of an HTTP request">
<button>Save changes</button>

Alt text matters most when the image fails to load or the visitor cannot see it. Labeling inputs and grouping related fields with fieldset and legend keeps forms navigable.

ARIA Only When Needed

ARIA attributes extend semantics when native HTML cannot express the meaning, such as live regions or tab lists. First preference should always be a native HTML element, because native behavior is free accessibility.

Performance Fundamentals

Speed is measured with metrics like LCP, which tracks when the main content appears. The everyday practices matter more than exotic tuning.

Compress images and serve them in modern formats at the right size.
Minify CSS and JavaScript.
Remove render-blocking scripts from the critical path.
Cache static assets with long expiry headers.
Use lazy loading for images below the fold.

<img src="hero.webp" alt="Welcome illustration" loading="lazy">

The loading attribute delays decoding for images that are not immediately visible. Server responses should also set Cache-Control so repeat visits reuse files instead of downloading them again.

Measure, Then Improve

Open the Lighthouse tool or the Chrome DevTools Performance panel to get scores for performance, accessibility, and SEO. Fix the biggest problem, re-measure, and repeat. Small consistent improvements add up to a dramatically better experience.