Server Response Time (TTFB) Test
Measure DNS, connection, TLS and time to first byte over three requests.
About the Server Response Time (TTFB) Test
Time to First Byte (TTFB) is how long it takes from requesting a page until the first byte of the response arrives. Nothing can appear on screen before then, so a slow TTFB delays every other metric, including Largest Contentful Paint.
This test makes three requests from our server and breaks each one into DNS lookup, TCP connection, TLS handshake and server wait (the time your server spends generating the page). If server wait dominates, look at caching, database queries and hosting. If DNS or connection time is high, a CDN or a faster DNS provider helps. Results reflect the distance between our server and yours, so visitors in other regions may see different numbers.
Frequently asked questions
What is a good TTFB?
Google considers 0.8 seconds or less good and over 1.8 seconds poor, measured at the 75th percentile of real visits.
Why is the first request slower?
The first request may wake up a sleeping server process, warm caches or require a fresh DNS lookup.
How do I improve TTFB?
Use full-page caching, a CDN with edge caching, an efficient hosting plan, an up-to-date PHP/Node version and fewer database queries per page.