10 Website Performance Optimisations You Can Implement Today

Website performance isn't just about speed—it's about delivering a seamless user experience that keeps visitors engaged and converts them into customers. In this guide, we'll explore 10 practical optimisations you can implement today to significantly improve your website's performance.

1. Optimise Your Images

Images often account for the majority of a webpage's size. Optimising them can lead to dramatic performance improvements.

Implementation Steps:

• Use modern formats: Convert images to WebP, which provides superior compression compared to PNG and JPEG
• Implement responsive images: Use the srcset attribute to serve different image sizes based on device screen size
• Lazy load images: Only load images when they're about to enter the viewport
• Compress without quality loss: Use tools like ImageOptim, TinyPNG, or Squoosh to reduce file size while maintaining visual quality

<!-- Responsive images example -->
<img 
  src="image-800w.jpg" 
  srcset="image-400w.jpg 400w, image-800w.jpg 800w, image-1200w.jpg 1200w" 
  sizes="(max-width: 600px) 400px, (max-width: 1200px) 800px, 1200px"
  alt="Description"
  loading="lazy"
/>

2. Implement Effective Caching

Caching stores copies of files so they can be served faster on repeat visits.

Implementation Steps:

• Set appropriate cache headers: Configure Cache-Control and Expires headers to control how long browsers cache resources
• Leverage browser caching: Set long expiration times for static resources that don't change often
• Use ETags: Enable ETags to validate cached resources and prevent unnecessary downloads
• Implement service workers: Cache resources and enable offline functionality with service workers

# Apache .htaccess example
<IfModule mod_expires.c>
  ExpiresActive On
  ExpiresByType image/jpeg "access plus 1 year"
  ExpiresByType image/png "access plus 1 year"
  ExpiresByType text/css "access plus 1 month"
  ExpiresByType application/javascript "access plus 1 month"
</IfModule>

3. Minify CSS, JavaScript, and HTML

Minification removes unnecessary characters from your code without changing functionality.

Implementation Steps:

• Remove whitespace, comments, and unused code: Use tools like Terser for JavaScript and CSSNano for CSS
• Combine multiple CSS and JavaScript files: Reduce HTTP requests by bundling files together
• Use build tools: Implement webpack, Parcel, or Vite to automate minification in your build process

4. Enable Compression

Compression reduces the size of files sent from your server to the browser.

Implementation Steps:

• Enable Gzip or Brotli compression: Configure your server to compress text-based resources
• Compress all appropriate file types: Include HTML, CSS, JavaScript, XML, and JSON files

# Nginx configuration example
gzip on;
gzip_comp_level 6;
gzip_min_length 256;
gzip_types text/plain text/css application/json application/javascript text/xml application/xml text/javascript;

5. Optimise Critical Rendering Path

The critical rendering path is the sequence of steps the browser takes to convert HTML, CSS, and JavaScript into pixels on the screen.

Implementation Steps:

• Minimise render-blocking resources: Load critical CSS inline and defer non-critical CSS
• Defer JavaScript loading: Use defer or async attributes for non-critical scripts
• Prioritise visible content: Ensure above-the-fold content loads quickly

<!-- Defer non-critical JavaScript -->
<script src="non-critical.js" defer></script>

<!-- Async loading when order doesn't matter -->
<script src="analytics.js" async></script>

6. Implement Content Delivery Network (CDN)

A CDN distributes your content across multiple locations worldwide, reducing latency for users.

Implementation Steps:

• Choose a CDN provider: Popular options include Cloudflare, Akamai, and Amazon CloudFront
• Configure your CDN: Set up proper caching rules and SSL certificates
• Serve static assets through the CDN: Images, CSS, JavaScript, and other static files

7. Reduce HTTP Requests

Each resource your page requests adds loading time, especially on slower connections.

Implementation Steps:

• Combine files: Merge multiple CSS or JavaScript files
• Use CSS sprites: Combine multiple images into one file
• Implement icon fonts or SVGs: Replace multiple icon images with a single font file or inline SVGs
• Remove unnecessary resources: Audit your site and remove unused CSS, JavaScript, and plugins

8. Optimise Web Fonts

Web fonts enhance design but can slow down your site if not optimised properly.

Implementation Steps:

• Limit font weights and styles: Only load the variations you actually use
• Use font-display property: Control how fonts are loaded and displayed
• Consider system fonts: Use system font stacks for better performance
• Subset fonts: Include only the characters you need

/* Font-display example */
@font-face {
  font-family: 'MyWebFont';
  src: url('webfont.woff2') format('woff2');
  font-weight: 400;
  font-style: normal;
  font-display: swap; /* Prevents invisible text while loading */
}

9. Implement Lazy Loading

Lazy loading defers loading of non-critical resources until they're needed.

Implementation Steps:

• Lazy load images and videos: Use the loading="lazy" attribute or Intersection Observer API
• Implement code splitting: Break your JavaScript into smaller chunks that load on demand
• Use dynamic imports: Load JavaScript modules when needed

// Dynamic import example
button.addEventListener('click', async () => {
  const module = await import('./feature.js');
  module.doSomething();
});

10. Monitor and Analyse Performance

Continuous monitoring helps you identify and fix performance issues as they arise.

Implementation Steps:

• Use performance monitoring tools: Implement Lighthouse, WebPageTest, or Google PageSpeed Insights
• Set up Real User Monitoring (RUM): Track actual user experiences with tools like Google Analytics or dedicated RUM solutions
• Monitor Core Web Vitals: Track LCP, FID, and CLS metrics
• Establish performance budgets: Set limits for page size, load time, and number of requests

Conclusion

Implementing these optimisations will significantly improve your website's performance, leading to better user experience, higher conversion rates, and improved search engine rankings. Remember that performance optimisation is an ongoing process—regularly test your site and continue making improvements.