TTFB

TTFB (Time to First Byte) measures how long a browser waits, after asking for a page, before the first byte of the reply arrives. It covers the connection, any redirects, and the time your server takes to build the page.

Up to 0.8 seconds is considered good; beyond 1.8 seconds is poor. TTFB is not one of Google's Core Web Vitals and does not decide whether a page passes, but nothing can appear until the first byte arrives, so a slow server delays LCP and everything after it. When LCP is slow, TTFB tells you whether to look at the server or the page.

If you use Analytics, Silktide reports TTFB from real visits at the 75th percentile. Slow TTFB usually means slow server code or database queries, no caching, or visitors far from your server without a CDN.

Learn more

• Time to First Byte (TTFB) - Google's metric definition and thresholds
• Optimize TTFB - practical fixes
• Core Web Vitals