TTFB · Server response

Time to First Byte: how long until the first byte of the page arrives.

TTFB verdict

v1.2.1 vs v1.2.0 · / · mobile

Nowv1.2.0

Unchanged

Server response didn’t change. A change only counts when it is at least 5% and at least 50ms. Here that means 50ms, so this one doesn’t.

faster−50ms · too small to count · +50msslower

Now · v1.2.1

552ms

Good

v1.2.0552msChange0msGood up to800ms

Visits measured

171

on mobile, enough for a verdict

v1.2.0 · mobile224 / 30

v1.2.1 · mobile171 / 30

v1.2.1 · desktop62 / 30

Where visits landed

share of visits in each range

v1.2.092%

v1.2.192%

Good ≤ 800msNeeds improvementPoor > 1,800ms

Same shape as v1.2.0. Nine in ten mobile visits get their first byte in 800ms or less.

The steps that add up to the first byte. A place to look, not a cause.

Typical visit · each point is a deploy, ringed by its TTFB verdict

ImprovedRegressedUnchanged

v1.2.1 vs v1.2.0 · mobile · pages need 30 visits on both sides

PageVisitsv1.2.0v1.2.1ChangeVerdict

171552ms552ms+0.0%Unchanged

122600ms600ms+0.0%Unchanged

146630ms630ms+0.0%Unchanged

49540ms540ms+0.0%Unchanged