2025 Web Performance Best Practices
The ultimate guide to optimizing your site's performance in the modern web development landscape.
Average LCP in 2025
CDN efficiency
Minified JS load time
2025 Performance Standards
Core Web Vitals
Meet LCP ≤1.8s, FID ≤300ms, and CLS < 1.0 using modern optimization techniques like Pre-connection and Resource Hints.
WebAssembly Usage
Use Wasm for CPU-intensive tasks and offload work from JavaScript - improving rendering speeds by up to 300% in 2025.
CDN Optimization
Implement SmartPrefetch with edge delivery networks to reduce time to first byte by 40-60% for global audiences.
Mobile-First Index
Prioritize mobile LCP metrics with 100% progressive enhancement, and ensure 0% layout shift on all device types.
Practical Implementation
Preconnection Example
// Preconnect to third-party resources before they're needed
link(rel='preconnect', href='https://example-cdn.com');
Reduces DNS lookup latency by 70%+ on global connections.
Code Splitting Strategy
// Modern code splitting with Webpack 5
new webpack.optimize.SmartSplitChunksPlugin({
maxSize: 1024 * 256 // 256kb per file
});
Improves 80%+ of pages by reducing initial load times.
2025 Testing Toolkit
Lighthouse 12.5
Chrome DevTools update with Wasm benchmarking support for core metrics.
WebPageTest
2025 beta with native WebGPU trace integration now available via CLI.
Fathom v4
Open source analytics with 0% data collection bias, now WebAssembly compatible.
Ready to Test Your Performance?
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