Web Dev Checklist

Use proper DOCTYPE, html, head, and body tags. Validate with W3C validator.

Use header, nav, main, article, section, aside, and footer instead of generic divs.

Include <meta name='viewport' content='width=device-width, initial-scale=1'>.

Minify CSS files and bundle them to reduce HTTP requests and file sizes.

Remove unused JavaScript. Use tree shaking in your build process.

Use loading='lazy' for below-the-fold images. Lazy load video embeds.

Serve images in WebP or AVIF with fallbacks for older browsers.

Use srcset and sizes attributes to serve appropriately sized images.

Subset fonts to only needed characters. Preload critical fonts.

Inline above-the-fold CSS to prevent render-blocking.

Use defer or async attributes on non-critical script tags.

Ensure your server supports HTTP/2+ for multiplexing and header compression.

Enable Brotli or Gzip compression on your server for text-based assets.

Serve images, CSS, and JS from a CDN for faster global delivery.

Set Cache-Control and ETag headers for static assets.

Ensure color contrast, keyboard navigation, ARIA labels, and screen reader compatibility.

Every non-decorative image needs descriptive alt text.

All interactive elements should be reachable and usable via keyboard.

Don't remove focus outlines. Style them to be visible and match your design.

Add aria-label or aria-labelledby to buttons, links, and form elements that need context.

Serve all pages over HTTPS. Use HSTS header for strict transport security.

Implement CSP to prevent XSS attacks and unauthorized script execution.

Prevent clickjacking by setting X-Frame-Options to DENY or SAMEORIGIN.

Ensure all resources (images, scripts, styles) are loaded over HTTPS.

Validate all user inputs on both client and server side to prevent injection attacks.

Create custom 404 and 500 error pages that maintain site branding and navigation.

Redirect old URLs to new ones with 301 status codes to preserve link equity.

Check browser console for JavaScript errors and fix them before launch.

Test in Chrome, Firefox, Safari, and Edge. Check mobile browsers too.

Set limits for page weight, number of requests, and load time. Monitor continuously.

Write tests for critical functionality. Set up CI/CD to run tests automatically.

Never hardcode API keys or secrets. Use environment variables.