Concept

TTFB (Time to First Byte)

Time from the start of an HTTP request to the receipt of the first byte of the response; a core latency metric.

Published February 20, 2026

Definition

TTFB (Time to First Byte) is the time between the client (browser or crawler) sending a request and receiving the first byte of the response. It reflects server and network latency before any content is delivered. A high TTFB delays LCP and can cause AI crawlers with short timeouts to skip or truncate the page.

Relevance to GEO

AI retrieval crawlers often use timeouts of a few seconds. Improving TTFB (e.g. via CDN, server tuning, edge rendering) increases the chance that full content is fetched and indexed for RAG or answers.

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