Technical SEOPublished30.05.2026

TTFB (Time to First Byte): What It Is and How to Improve It

Time to First Byte is the time from sending a request to receiving the first byte of a server response. A key server performance metric that directly affects Core Web Vitals and rankings.

In brief

TTFB (Time to First Byte) is the time between sending an HTTP request and the browser receiving the first byte of the server response. A good TTFB is under 800 ms. Affects LCP and overall page load speed.

What is TTFB

Time to First Byte (TTFB) is the time between a browser sending an HTTP request and receiving the first byte of the server response. The metric measures the total latency: DNS resolution time, TCP connection setup, TLS handshake, and server processing time.

Unlike LCP or CLS, TTFB is not part of the official Core Web Vitals set, but it is the most important precursor to all client-side metrics — a poor TTFB automatically degrades LCP and overall page load time.

How to Measure TTFB

  • Google PageSpeed Insights — shows TTFB in Lab Data under Server Response Time
  • Chrome DevTools → Network → request header → Waiting for server response
  • WebPageTest — detailed waterfall diagram with phase breakdown
  • Lighthouse in Chrome — audit: Reduce initial server response time

Google Benchmarks

TTFBRating
< 800 msGood (green)
800 ms – 1800 msNeeds improvement (orange)
> 1800 msPoor (red)
Google recommends achieving TTFB < 800 ms, but for high-traffic sites < 200 ms via CDN caching is considered optimal.

How to Improve TTFB

  • CDN and response caching — the most effective method: a cached response from the nearest CDN node is delivered in 10–50 ms
  • Server-level caching — Redis, Varnish, or built-in CMS page cache
  • Optimizing slow SQL queries and N+1 database issues
  • SSR with Incremental Static Regeneration (ISR) instead of full SSR on every request
  • Choosing a data center geographically close to your audience

TTFB and SEO

Google officially confirmed that server speed is a ranking signal since 2010. TTFB affects SEO in two ways: directly as one of the page speed signals, and indirectly by degrading LCP, which is part of Core Web Vitals and counted in the Page Experience signal.

FAQ

Common questions

Google considers TTFB under 800 ms good. For competitive niches, aim for < 200 ms using a CDN.
Not directly — TTFB is not a CWV metric. But a poor TTFB automatically increases LCP, which is a Core Web Vitals metric.
Setting up a CDN with static page caching is the fastest approach: TTFB drops to 10–50 ms within hours.
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