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?



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