[SOLVED] How do I understand if my web app has a good performance?

How do I understand if my web app has a good performance?

I am using reportwebvitals in react to gather performance-related data. I see values such as:

{name: "LCP", value: 865.895, delta: 865.895, entries: Array(1), id: "v1-1619568902884-5783450530819"}
{name: "FID", value: 3.389999968931079, delta: 3.389999968931079, entries: Array(1), id: "v1-1619568902884-3190618744586"}

I understand that a good LCP score is below 2.5sec and a good FID score is below 100 ms. Given the values which key exactly indicates this score?

I tried to go through the available documentation but was not able to understand how to derive these time results. Can somebody please help?

Thanks!

Solution

This appears to be based on web-vitals.js. The README has a lot more information about how to interpret the output and when to use delta versus value. To answer your question, the value field tells you the scores for each metric:

LCP = 866 milliseconds

FID = 3 milliseconds