How to Optimise Your Website for Speed in 2025

🖼️ 1. Optimised Image Formats & Compression Techniques

Images are usually the number one cause of slow page loads. Optimising them is your fastest win.

🔍 Why it matters:

Heavy images increase page weight, slow initial load, and negatively impact LCP (Largest Contentful Paint), a key Core Web Vital.

🛠 How to optimise:

• Convert to next-gen formats like WebP or AVIF
• Compress without quality loss using tools, you can usually install a plugin. or if your site is built in a modern framework its often an option in the development
• Use responsive image sizes with srcset or the Next.js Image component
• Lazy load off-screen images to save bandwidth

On my personal site, switching hero banners from PNG to WebP cut file sizes by 85%. This alone shaved 2.4s from load time on mobile.

⚙️ 2. Minifying JavaScript & CSS + Deferring Non-Essential Scripts

JavaScript and CSS are essential, but they must be lean and loaded smartly.

🔍 Why it matters:

Excessive scripts slow down rendering, delay interactivity, and cause layout shifts.

🛠 How to optimise:

• Minify files using Terser, esbuild, or native support in build tools like Next.js
• Defer or async-load non-essential scripts
• Split code to reduce the initial JS payload

In my setup, deferring third-party analytics and using async on non-essential scripts with the Next.js <Script> component helped reduce TBT below 30 ms — a good benchmark for smooth interactivity.

💤 3. Lazy Loading Techniques to Improve Page Speed

Don't make the browser load everything upfront.

🔍 Why it matters:

Loading resources only when needed drastically reduces initial payload and improves First Contentful Paint (FCP).

🛠 How to optimise:

• Use loading="lazy" on images and iframes
• Load below-the-fold sections only when in view (Intersection Observer)
• Consider lazy-loading components or routes with dynamic imports in Next.js

On my homepage, lazy loading reduced first-load JS by 40%. It feels snappier — even with animation-heavy sections because you start seeing the page in 0.2s on desktop, and under 1s on slow mobile internet.

🧹 4. Audit & Minimise Third-Party Scripts for Faster Load Times

Every third-party script is a trade-off. Some are worth it, many aren’t.

🔍 Why it matters:

External scripts often block rendering, increase TTFB (Time to First Byte), and cause layout shifts.

🛠 How to optimise:

• Audit all plugins, embeds, widgets, and tracking pixels
• Replace with lighter alternatives (e.g. Plausible Analytics vs GA4)
• Load non-critical ones after user interaction

I removed unnecessary social embeds, old analytics tags, and legacy plugins - recovering nearly 1.2s on mobile 4G.

🌐 5. Leverage CDNs and Edge Networks for Global Performance

A Content Delivery Network (CDN) brings your content closer to the user.

🔍 Why it matters:

Faster geographic delivery reduces latency, improves Time to First Byte (TTFB), and handles global traffic spikes.

🛠 How to implement:

• Choose hosts with built-in global CDNs (Vercel, Netlify)
• Or integrate Cloudflare, BunnyCDN, or CloudFront
• Cache both static and dynamic content at the edge

My Next.js site runs on Vercel, which pushes content across their Edge Network by default. Visitors from Tokyo or Berlin get near-identical performance to London.

🧠 6. Choose High-Performance Hosting for Speed and Scalability

Your host defines your performance ceiling.

🔍 Why it matters:

Shared hosting can throttle CPU, delay content delivery, and bottleneck concurrency, especially during traffic spikes.

🛠 How to improve:

• Choose serverless platforms (like Vercel or Netlify)
• Use auto-scaling VPS or containers for custom apps
• Prioritise edge functions, fast DNS, and uptime SLAs

Vercel’s edge rendering, CDN integration, and zero-config deploys allowed me to focus on design, not servers.

📊 7. Track and Improve Core Web Vitals: LCP, FCP, CLS

You can’t optimise what you can’t measure.

🔍 Why it matters:

Google uses Core Web Vitals as a ranking signal. They also directly impact UX and engagement.

🛠 Tools to use:

• PageSpeed Insights
• Lighthouse
• WebPageTest
• Real-user tools: Google Search Console, Vercel Analytics

Key metrics:

• LCP (Largest Contentful Paint): Main content load time — aim for less than 2.5s
• FCP (First Contentful Paint): Time at which the first text or image is painted — aim for less than 1s
• CLS (Cumulative Layout Shift): Layout stability — aim for 0.1 or less

A green score on these markers are what you're aiming for to reliably provide a good experience for all users, how does your site compare?

You can test your site for yourself here, and see how it stacks up against my website.

🧱 8. Implement Smart Caching Strategies with ISR and More

Caching reduces server workload and delivers faster content.

🔍 Why it matters:

Every server call adds delay. Caching delivers pre-built or pre-fetched content, saving time and resources.

🛠 How to optimise:

• Static Site Generation (SSG) or Incremental Static Regeneration (ISR) in Next.js
• Browser caching for assets
• API response caching with SWR or server middleware
• Edge caching via your hosting platform or CDN

I use ISR for my blog, ensuring users always see the latest content, while still loading at lightning speed.

💬 Bonus Tips

• Font Optimisation: Use font-display: swap, preload key fonts, and self-host if possible.
• Remove unused CSS: Use PurgeCSS or built-in Tailwind/Next.js features.
• Avoid animations that block paint: Offload to transform and opacity.

🔚 Conclusion: Build a Lightning-Fast, SEO-Ready Website in 2025

Speed isn't just a feature, it's foundational. In 2025, website performance is UX, SEO, and brand reputation all rolled into one.

By applying modern performance techniques like lazy loading, edge caching, and image optimisation, paired with a fast platform like Vercel and smart development tools like Next.js, you build something far better than fast. You build trust.

This guide reflects my real-world journey of building a fast, beautiful, responsive website. Every strategy listed here is part of my current live setup.

📩 Want to see what this looks like in practice or need help getting your site up to speed? Let’s chat.