Web Performance in 2025: The Complete Guide

Web performance remains crucial for user experience, SEO, and business outcomes. As Rishikesh Baidya, our CTO, puts it: every 100ms of latency costs you conversions. Here's our complete guide for 2025, based on optimizing projects like TalkDrill and AppliedView.

Core Web Vitals Update

Current Metrics

Measuring Performance

• PageSpeed Insights - Lab and field data from Google
• Chrome DevTools Performance panel - Detailed debugging
• Web Vitals library - In-app tracking
• Real User Monitoring (RUM) - Actual user experience data

Loading Performance

Image Optimization

// Next.js Image with all optimizations

Font Optimization

import { Inter } from 'next/font/google'
const inter = Inter({
  subsets: ['latin'],
  display: 'swap',
  variable: '--font-inter',
})

JavaScript Optimization

// Dynamic import for heavy components
const HeavyComponent = dynamic(
  () => import('./HeavyComponent'),
  { loading: () =>  }
)

Interaction Performance (INP)

React Optimization

// Avoid unnecessary renders
const MemoizedComponent = memo(function Component({ data }) {
  return 
{data.value}
})
// Stable callbacks
const callback = useCallback(() => {
  // expensive operation
}, [dependency])
// Cached computations
const computed = useMemo(() => {
  return expensiveComputation(data)
}, [data])

Event Handler Best Practices

Visual Stability (CLS)

Preventing Layout Shifts

/ Reserve space with aspect-ratio /
.image-container {
  aspect-ratio: 16 / 9;
}
/ Or explicit dimensions /
.ad-slot {
  min-height: 250px;
}

• Always set width/height on images and videos
• Reserve space for ads and embeds
• Never insert content above existing content
• Use CSS containment for dynamic sections
• Preload fonts to prevent FOUT

Caching Strategies

HTTP Caching

# Immutable assets (hashed filenames)
Cache-Control: public, max-age=31536000, immutable
# HTML pages
Cache-Control: public, max-age=0, must-revalidate

Service Workers

Server-Side Optimization

Edge Computing

Move processing closer to users:
• Edge functions for personalization
• CDN optimization for static assets
• Regional deployment for data compliance

Streaming with Suspense

}>
  

Monitoring

Real User Monitoring

Track actual user experience, not just lab scores:
• Performance metrics by device/network
• Error rates and types
• Geographic distribution
• User segment analysis

Related Resources