# Time to First Byte (TTFB)

DevFeed: [Time to First Byte (TTFB)](<https://devfeed.tech/articles/time-to-first-byte-ttfb-4165.md>)

Original publisher: [Read original article](<https://web.dev/articles/ttfb?hl=en>)

Author: Barry Pollard X GitHub Mastodon Bluesky Homepage Jeremy Wagner GitHub LinkedIn Homepage

Published: 2025-11-28T08:00:00Z

Content type: article

Language: en

Sources: [web.dev: Articles](<https://devfeed.tech/sources/web-dev-articles.md>)

Topics: [Latency](<https://devfeed.tech/topics/latency.md>), [browser](<https://devfeed.tech/topics/browser.md>), [Chrome](<https://devfeed.tech/topics/chrome.md>), [JavaScript](<https://devfeed.tech/topics/javascript.md>), [API](<https://devfeed.tech/topics/api.md>), [HTTP](<https://devfeed.tech/topics/http.md>)

Tags: [api](<https://devfeed.tech/tags/api.md>), [browser](<https://devfeed.tech/tags/browser.md>), [chrome](<https://devfeed.tech/tags/chrome.md>), [guide](<https://devfeed.tech/tags/guide.md>), [http](<https://devfeed.tech/tags/http.md>), [javascript](<https://devfeed.tech/tags/javascript.md>), [latency](<https://devfeed.tech/tags/latency.md>), [post](<https://devfeed.tech/tags/post.md>)

## AI overview

This post explains Time to First Byte (TTFB), a metric measuring the time from navigation start until the first response byte begins to arrive. It covers the request phases that contribute to TTFB, the effects of 103 Early Hints and early response flushing, recommended performance targets, and methods for measuring TTFB in browsers and developer tools.

## Source excerpt

This post explains the Time to First Byte (TTFB) metric and shows how to measure it.