A fast website is not a luxury — it is a baseline expectation. Research consistently shows that even a one-second delay in page load time can reduce conversions by up to seven per cent, increase bounce rates, and hurt your search rankings. The good news is that most speed improvements are straightforward to implement and deliver measurable results quickly.
Before diving into these optimisations, run your site through Site Speed Check to establish a baseline. Knowing your current performance score and which metrics need the most attention will help you prioritise the right changes.
1. Optimise Images
Images are typically the heaviest resources on any web page, often accounting for 50 per cent or more of total page weight. Optimising them is almost always the single most impactful improvement you can make.
Resize images to the maximum dimensions they will actually be displayed at — there is no point serving a 4000-pixel-wide image for a slot that is 800 pixels wide. Compress them using tools like Squoosh, TinyPNG, or your CMS's built-in optimisation. Aim for the smallest file size that maintains acceptable visual quality.
2. Enable Compression
Gzip and Brotli compression reduce the size of text-based resources (HTML, CSS, JavaScript, SVG, JSON) by 60 to 80 per cent before they are sent to the browser. Most modern web servers support Brotli, which achieves better compression ratios than Gzip.
Check your server configuration or CDN settings to ensure compression is enabled. If you are using Apache, enable mod_deflate. For Nginx, add gzip on; and brotli on; to your configuration.
3. Minify CSS and JavaScript
Minification strips whitespace, comments, and unnecessary characters from your code without changing its functionality. This reduces file sizes and speeds up download and parse times. Most build tools (Webpack, Vite, esbuild) handle this automatically in production mode.
Beyond minification, audit your CSS and JavaScript for unused code. Shipping unused styles and scripts wastes bandwidth and slows down parsing. Tools like Chrome DevTools' Coverage tab can show you exactly how much of each file is actually used on a given page.
4. Use a Content Delivery Network (CDN)
A CDN distributes copies of your static assets across servers worldwide, so users download files from a location geographically close to them. This significantly reduces latency, especially for international audiences.
Popular CDN providers include Cloudflare, AWS CloudFront, Fastly, and Bunny CDN. Many offer free tiers that are sufficient for small to medium websites. If your site serves a global audience, a CDN is one of the most cost-effective performance investments you can make.
5. Leverage Browser Caching
When a browser downloads an asset for the first time, caching headers tell it how long to keep that file before requesting it again. Properly configured caching means returning visitors load your site almost instantly because most resources are served from their local cache.
Set long cache durations (at least one year) for static assets like images, fonts, CSS, and JavaScript files. Use cache-busting techniques — such as appending a hash to filenames — so browsers fetch new versions when you deploy updates. Set shorter cache durations for HTML pages so content updates are reflected promptly.
6. Reduce HTTP Requests
Every resource your page requires — images, stylesheets, scripts, fonts, tracking pixels — generates a separate HTTP request. While HTTP/2 and HTTP/3 have reduced the overhead of individual requests through multiplexing, fewer requests still means less work for the browser.
Combine CSS files where practical, inline critical CSS, use CSS sprites or SVG for small icons, and eliminate unnecessary third-party scripts. Every request you remove contributes to a faster page load.
7. Optimise Server Response Time
Your Time to First Byte (TTFB) reflects how long your server takes to begin sending a response. A slow TTFB affects every subsequent metric because nothing else can start until the browser receives that first byte of HTML.
Common fixes include implementing server-side caching (like Redis or Varnish), optimising database queries, upgrading your hosting plan, and using an application-level cache for dynamically generated pages. If your TTFB consistently exceeds 200 milliseconds, investigate your server infrastructure.
8. Lazy Load Images and Embeds
Lazy loading defers the download of off-screen images and embeds until the user scrolls near them. This means the browser only loads the resources needed for the initial viewport, dramatically reducing initial page weight and load time.
Modern browsers support native lazy loading with the loading="lazy" attribute on <img> and <iframe> elements. It is simple to implement and has excellent browser support. Just make sure you do not lazy load above-the-fold images — your LCP element should always load eagerly.
9. Use Modern Image Formats (WebP and AVIF)
WebP typically produces files 25 to 35 per cent smaller than equivalent JPEG images at the same visual quality. AVIF goes further, often achieving 50 per cent smaller files than JPEG. Both formats support transparency (replacing PNG) and animation (replacing GIF).
Use the <picture> element to serve AVIF with WebP and JPEG fallbacks, or configure your CDN to handle format negotiation automatically via the Accept header. Most modern CMS platforms and image CDNs can generate WebP and AVIF on the fly.
10. Remove Render-Blocking Resources
Render-blocking resources are CSS and JavaScript files that must be downloaded and processed before the browser can paint anything on screen. They directly delay First Contentful Paint and Largest Contentful Paint.
Inline the critical CSS needed for above-the-fold content directly in the <head>, and load the remaining CSS asynchronously. Add defer or async attributes to JavaScript files that are not required for initial render. Move non-essential scripts to the bottom of the page or load them dynamically after the page becomes interactive.
Measure the Impact
After implementing these changes, run your site through Site Speed Check again to measure the improvement. Compare your before and after scores, and pay particular attention to Core Web Vitals — these are the metrics that directly influence your search rankings and user experience.
Performance optimisation is an ongoing process, not a one-time task. New content, third-party scripts, and feature additions can gradually erode your performance gains. Regular testing helps you catch regressions early and maintain a consistently fast experience for your users.