Google's search algorithm prioritizes fast user experiences. While frontend engineers focus on minifying JavaScript and compressing WebP images, the foundation of page speed rests entirely on Server Time-To-First-Byte (TTFB).
What is TTFB and Why Does Google Care?
TTFB measures the duration from when a client sends an HTTP request to when the browser receives the first byte of response data. It includes DNS lookup, TCP handshake, TLS negotiation, and server side processing time.
"If your server TTFB is 800ms, your Largest Contentful Paint (LCP) can NEVER be faster than 800ms—no matter how small your CSS or images are."
1. Direct Link Between TTFB and Core Web Vitals (LCP)
Google's official Core Web Vitals threshold requires LCP < 2.5 seconds for a "Good" rating. Our telemetry shows:
- TTFB < 100ms 98% Pass Rate 🥇
- TTFB 200ms-400ms 72% Pass Rate
- TTFB > 600ms High Risk Fails LCP
⚡ Boost Your Core Web Vitals
Upgrade to high-performance low-TTFB servers verified by our global telemetry network: