p75
p75, the number behind every verdict.
p75 is short for the 75th percentile. Line up every visit from fastest to slowest, and p75 is the one three quarters of the way along. In plain words: three in four visits were this fast or faster.
Four visits, fastest first
- 1.4s
- 1.9s
- 2.5s
- 4.7s
Three in four were 2.5s or faster. That’s what “p75 is 2.5s” means.
See it happen
Find the p75 in 100 visits.
Watch 100 visits to one page arrive, line up fastest first, then count three quarters of the way along. Tap p50, p95 or p99 to see where they land next to p75.
p75 vs the average
One bad visit shouldn’t tell the whole story.
Someone opens your page on a train going into a tunnel and waits 30 seconds. The average adds every visit up and divides, so that one visit drags it way up. p75 only cares where visits sit in the line, so it moves one small step.
p75 vs other percentiles
Why p75, and not p50, p95 or p99?
The higher the number, the slower the visitors it describes. p75 sits where it still counts your slower visitors but doesn’t jump around when one visit goes wrong.
- p50The typical visit
Median · in the example, 1.87s
Half the visits were faster, half were slower.
What an ordinary visit feels like. It says nothing about the people who waited.
Next to p75: it ignores the slow half, so a slower quarter of visits goes unnoticed.
- p75Most visitors
75th percentile · in the example, 2.55s
Three in four visits were this fast or faster.
Covers most of your visitors, slower phones included, without being thrown by one bad visit.
Used for every CodeGecko verdict, and by Google for Core Web Vitals.
- p95The slow tail
95th percentile · in the example, 4.34s
Only 5 in 100 visits were slower than this.
The people on old phones and weak networks. Useful, but a few visits can move it a lot.
Next to p75: one or two slow visits can swing it. Our status page uses it for response time.
- p99The worst cases
99th percentile · in the example, 5.22s
Only 1 in 100 visits was slower than this.
Almost the slowest visit you had. With 30 visits it is simply the slowest one, so it jumps around.
Next to p75: with 30 visits it’s just the slowest one. It needs thousands to settle.
In CodeGecko
Where you’ll see p75.
Any time you see p75 underlined on this site, it links back here. The full rules are on the methodology page.
- Every verdict compares this release’s p75 with the release before, per page, device and metric.
- Health badges rate the p75 against Google’s Core Web Vitals ranges.
- A verdict waits for 30 visits on each side, enough for the p75 to settle.
See the rules on real releases.
