TTFB Optimization — Time to First Byte Best Practices

Time to First Byte (TTFB) Optimization

TTFB measures the time from the start of the navigation request until the first byte of the response arrives at the browser. It is a foundational metric — every other metric (FCP, LCP) is delayed by a slow TTFB.

What TTFB Includes

TTFB is the sum of several network and server phases:

TTFB = DNS Lookup + TCP Connection + TLS Negotiation
     + Redirect Time + Server Processing Time
     + (Time to first byte of response)

TTFB Thresholds

Rating	Value
Good	≤ 800ms
Needs Improvement	≤ 1800ms
Poor	> 1800ms

Common Causes of Slow TTFB

1. No CDN (Content Delivery Network) Without a CDN, users far from your origin server experience high latency. A user in Tokyo requesting a page from a server in Virginia adds ~150ms of network round-trip time.

2. Slow Server-Side Processing Complex database queries, unoptimized API calls, heavy server-side rendering, and lack of response caching all increase server processing time.

3. Multiple Redirects Each redirect (HTTP 301/302) requires a full network round-trip. A chain of redirects (http→https→www→final) can add 300-500ms.

4. No Response Caching If every request hits the origin server and runs the full rendering pipeline, TTFB will be slow under load.

Optimization Strategies

Deploy a CDN:

• Cache HTML at the edge for static and semi-static pages
• Use regional edge functions (Cloudflare Workers, Vercel Edge) for dynamic content
• Pre-warm caches for high-traffic pages

Optimize Server Processing:

• Add database query caching (Redis, Memcached)
• Use connection pooling for database connections
• Profile and optimize slow API endpoints
• Consider ISR (Incremental Static Regeneration) for Next.js

Reduce Redirects:

• Serve final URLs directly (avoid http→https→www chains)
• Use HSTS preload to skip http→https redirect
• Audit third-party redirect chains

Enable Compression:

# Nginx Brotli configuration
brotli on;
brotli_types text/html text/css application/javascript application/json;
brotli_comp_level 6;

Use HTTP/2 or HTTP/3: Multiplexed connections reduce overhead. HTTP/3 (QUIC) eliminates TCP head-of-line blocking.