How to Make Your Website Faster: 25 Proven Techniques

Why website speed matters more than ever

Website speed directly impacts your bottom line. Studies show that a 1-second delay in page load time leads to 7% fewer conversions, 11% fewer page views, and 16% decrease in customer satisfaction.

Google has made page speed a ranking factor, with Core Web Vitals directly affecting search visibility. Sites that pass all three Core Web Vitals see measurably better rankings than those that don't.

Mobile users are especially impatient. With 53% of mobile visits abandoned if pages take longer than 3 seconds to load, speed optimization is essential for capturing and retaining traffic.

Image optimization techniques

Images typically account for 50-80% of page weight. Optimizing images is often the highest-impact speed improvement you can make.

Use modern formats like WebP and AVIF, which provide 25-50% smaller file sizes than JPEG and PNG with equivalent quality. All modern browsers support WebP, and AVIF support is growing.

Implement responsive images with srcset to serve appropriately sized images for each device. A 2000px image displayed at 400px wastes bandwidth and slows load times.

• Convert images to WebP or AVIF format
• Use srcset for responsive images
• Lazy load below-the-fold images
• Set explicit width and height attributes
• Compress images (aim for 85% quality for photos)
• Use CSS for simple graphics instead of images

JavaScript optimization

JavaScript is often the biggest performance bottleneck. It blocks rendering, consumes CPU during parsing and execution, and can dramatically increase Time to Interactive.

Implement code splitting to load only the JavaScript needed for the current page. Modern bundlers like Webpack, Vite, and Next.js support automatic code splitting.

Defer non-critical JavaScript using async or defer attributes. Critical functionality should load first; analytics, chat widgets, and other enhancements can wait.

• Implement code splitting and lazy loading
• Use async or defer for non-critical scripts
• Remove unused JavaScript (tree shaking)
• Minimize third-party scripts
• Use Web Workers for heavy computation
• Avoid long-running synchronous operations

CSS optimization

CSS blocks rendering until it's fully loaded and parsed. Optimizing CSS delivery is crucial for fast First Contentful Paint and Largest Contentful Paint.

Inline critical CSS (above-the-fold styles) directly in the HTML head to enable instant rendering. Load remaining CSS asynchronously using techniques like loadCSS.

Remove unused CSS with tools like PurgeCSS. Many sites ship 90%+ unused CSS from frameworks and legacy code, dramatically increasing load times.

• Inline critical CSS in the document head
• Load non-critical CSS asynchronously
• Remove unused CSS with PurgeCSS
• Minimize and compress CSS
• Avoid @import (use link tags instead)
• Use CSS containment to isolate components

Server and hosting optimization

Your server response time (TTFB) sets the baseline for everything else. If your server takes 2 seconds to respond, your LCP cannot possibly be under 2 seconds.

Use a Content Delivery Network (CDN) to serve content from edge locations close to users. CDNs can reduce latency by 50-80% for geographically distributed audiences.

Implement server-side caching with Redis or Memcached to avoid redundant database queries and computation. Cache aggressively and invalidate strategically.

• Use a CDN (Cloudflare, Fastly, CloudFront)
• Enable server-side caching (Redis, Memcached)
• Optimize database queries (indexes, query optimization)
• Use HTTP/2 or HTTP/3 for multiplexing
• Enable Gzip or Brotli compression
• Consider static site generation where applicable

Browser caching strategies

Proper cache headers can eliminate repeat downloads entirely. A returning visitor shouldn't need to download your CSS, JavaScript, or images again if they haven't changed.

Use cache-control headers with long max-age values for static assets, combined with content-based file hashing to enable cache busting when files change.

Implement service workers for advanced caching strategies, enabling offline support and instant loading for repeat visits.

• Set long cache-control max-age for static assets
• Use content hashing for cache busting
• Implement service workers for offline caching
• Pre-cache critical resources
• Use stale-while-revalidate for dynamic content

Font optimization

Web fonts can significantly impact performance, causing invisible text (FOIT) or unstyled text (FOUT) while fonts load, and contributing to layout shifts.

Use font-display: swap to show fallback text immediately while custom fonts load. This improves perceived performance even if final layout shifts slightly.

Subset fonts to include only the characters you need. A full Google Font can be 100KB+, while a subset with only Latin characters might be 20KB.

• Use font-display: swap or optional
• Preload critical fonts
• Subset fonts to needed characters
• Use system fonts where possible
• Self-host fonts instead of using Google Fonts
• Limit font variations (weights, styles)

Core Web Vitals optimization summary

All the techniques above contribute to better Core Web Vitals. Here's how they map to specific metrics:

For LCP: optimize images, improve server response time, eliminate render-blocking resources, and preload the LCP element. Target under 2.5 seconds.

For INP: reduce JavaScript execution time, break long tasks, optimize event handlers, and minimize third-party scripts. Target under 200 milliseconds.

For CLS: set image dimensions, reserve space for dynamic content, avoid inserting content above existing content, and use transform animations. Target under 0.1.

• LCP < 2.5s: Server, images, render-blocking resources
• INP < 200ms: JavaScript, event handlers, long tasks
• CLS < 0.1: Image dimensions, reserved space, animations
• TTFB < 800ms: CDN, caching, server optimization