TTFB (Time to First Byte).
TTFB measures the time from sending an HTTP request to receiving the first byte of data from the server. Target value: under 600ms (good) according to Google. A high TTFB is often the main cause of poor LCP and FCP scores. Causes: slow hosting, no CDN, inefficient server code.
TTFB (Time to First Byte) — Explained in Detail
TTFB (Time to First Byte) measures the time elapsed between the browser sending an HTTP request and receiving the first byte of data from the server. It is an indicator of the speed of your server infrastructure and the efficiency of your backend code. Google recommends a TTFB under 600ms as 'good'; 600ms–1800ms as 'needs improvement'; over 1800ms as 'poor'.
Why is TTFB so important? A high TTFB is often the root cause of poor LCP and FCP scores — because if the server takes 2 seconds to respond, FCP is impossible under 2 seconds. Common causes of high TTFB: slow web hosting (cheap shared hosting packages), no CDN (server far from the user), inefficient database access, uncached server-side pages, too many server-side API requests, and missing HTTP compression (Gzip/Brotli).
Measures to improve TTFB: Use high-quality hosting (not the cheapest shared host). Configure a CDN — Cloudflare or Vercel Edge Network reduce TTFB through edge caching. Implement server-side caching. Optimize database queries. Enable HTTP/2 or HTTP/3. Enable Gzip/Brotli compression. With Next.js: use Edge Runtime or Static Generation for frequently accessed pages.
Related Page
Core Web VitalsFrequently Asked Questions About TTFB (Time to First Byte)
TTFB is visible in Google PageSpeed Insights as a metric under diagnostics. In Chrome DevTools: Network tab → click the first resource (the HTML page) → Timing → 'Waiting (TTFB)'. Tools like WebPageTest (webpagetest.org) show TTFB from various global locations — useful if you have international users.
TTFB is the time until the first byte from the server. Total load time is the time until all resources (HTML, CSS, JavaScript, images) are loaded. TTFB is essentially the server response time — the first step in the loading chain. A good TTFB does not guarantee a good overall load time, but a poor TTFB makes it impossible to achieve good Core Web Vitals.
For Next.js applications, Vercel (Edge Network) offers excellent TTFB values through global edge deployments. Cloudflare Workers and Pages are also very fast. For traditional hosting: all major cloud providers (AWS, Google Cloud, Hetzner) are significantly better than shared hosting. DLM Digital uses Vercel + Cloudflare as standard.
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