How to Reduce TTFB (Time to First Byte) — Server Speed Guide

Time to First Byte (TTFB) is how long it takes from the browser's request to receiving the first byte of the response. While not a Core Web Vital itself, TTFB directly affects LCP and FCP. Target: under 200ms.

Every 100ms of TTFB improvement cascades into faster LCP.

Serving your pages from a CDN edge location close to the user can cut TTFB by 100-500ms:

- Vercel — automatic edge deployment for Next.js

- Cloudflare Pages — global CDN with Workers

- AWS CloudFront — enterprise-grade CDN

For API routes, use edge runtimes:

// Next.js Edge API Route
export const runtime = 'edge'

export async function GET(request) {
  // Runs on Vercel Edge Network, ~10ms TTFB
  return Response.json({ data: 'fast' })
}

Use stale-while-revalidate for dynamic content:

// Next.js API route with ISR-style caching
export async function GET() {
  const data = await fetchFromDB()
  return Response.json(data, {
    headers: {
      'Cache-Control': 'public, s-maxage=60, stale-while-revalidate=600',
    },
  })
}

This serves cached content instantly and revalidates in the background.

Slow database queries are the #1 cause of high TTFB for dynamic pages: