Measurement
TTFB (Time to First Byte)
Time to First Byte (TTFB) is a web performance metric that measures the duration from when a browser sends an HTTP request to when it receives the first byte of the server response. It reflects the combined impact of DNS lookup time, TCP connection time, TLS handshake time, and server processing time. Google considers a TTFB under 800ms as "good."
TTFB is measured using Google PageSpeed Insights, Lighthouse, GTmetrix, WebPageTest, and Chrome DevTools Network panel. Google Search Console's Core Web Vitals report reflects real-user TTFB data via the Chrome UX Report. Reducing TTFB involves server optimization, CDN implementation, and caching improvements.
Authority Links
Related Terms
Technical SEO
CDN (Content Delivery Network)
Refers to the network technology that enables data to be transmitted over servers in certain locations.
Measurement
DCL (DOM Content Loaded)
Refers to the time frame from entering a web page to the loading of the content.
Measurement
FCP (First Contentful Paint)
Refers to the point at which the first pixel renders on a screen after a user navigates to a web page.
Measurement
PageSpeed Insights
A Google tool that provides information about page opening speeds and user experience metrics.