How the maximum speed is calculated in strava

Hi mates,

I try to manually calculate the max speed of a small segment and I don’t get the same value as show on strava.

I joined the GPX. (gpx.txt) or the JSON point bellow can be used to replicate it.

{ lat: 46.2873437, lon: 7.4867482, time: "2025-03-13T17:26:35Z" },
{ lat: 46.2873455, lon: 7.4867516, time: "2025-03-13T17:26:36Z" },
{ lat: 46.2873491, lon: 7.486762, time: "2025-03-13T17:26:37Z" },
{ lat: 46.2873544, lon: 7.4867875, time: "2025-03-13T17:26:38Z" },
{ lat: 46.2873642, lon: 7.4868367, time: "2025-03-13T17:26:39Z" },
{ lat: 46.2873739, lon: 7.4868956, time: "2025-03-13T17:26:40Z" },
{ lat: 46.2873885, lon: 7.4869504, time: "2025-03-13T17:26:41Z" },
{ lat: 46.2874045, lon: 7.4869974, time: "2025-03-13T17:26:42Z" },
{ lat: 46.2874034, lon: 7.4870324, time: "2025-03-13T17:26:43Z" },
{ lat: 46.2873929, lon: 7.487055, time: "2025-03-13T17:26:44Z" }

So in my test I get. Between two point (4 and 5) I have a distance of : 4.65 meters. in one second so 16.74km/h. The stava move show me a max speed of 14.3km/h

So I am calculating it wrong ? Or does Strava use some smoothing technics ?

Cheers

Alex