TTFB is an abbreviation for Time To First Byte. This metric measures the duration of time a web browser must wait before it receives the very first byte of data transmitted from a server after a request is made.
Time To First Byte is one of the technical metrics evaluated in a Core Web Vitals report, which is used to assess the overall loading experience and performance of a website.
TTFB serves as a measure of the server’s responsiveness. Since a quick response time is a key aspect of user experience, a poor TTFB score can cause visitors to abandon a website out of frustration. The lower the TTFB, the less time users spend waiting for a page to begin loading. This improved speed can directly contribute to higher engagement and user retention. TTFB can be measured in a lab environment using tools like WebPageTest and can be evaluated in real-world scenarios using the Chrome User Experience Report.
Common strategies for improving a TTFB score include upgrading web hosting infrastructure or implementing a Content Delivery Network (CDN).