To improve performance, you first need metrics: some measurable numbers to
verify the problems and improvements.
In the metrics page,
you’ll see which metrics are currently used,
and which tools and APIs are available to get the metrics.

There is a list of Frequently asked questions, 
so you can find out if the questions you have or the problems you’re having 
were already answered or encountered, and whether there are existing solutions. 
(Alternatively, you can check the Flutter GitHub issue database using the
performance label.)

Finally, the performance issues are divided into four categories. They 
correspond to the four labels that are used in the Flutter GitHub issue 
database: “perf: speed”, “perf: memory”, 
“perf: app size”, “perf: energy”.

The rest of the content is organized using those four categories.

Speed

Are your animations janky (not smooth)? Learn how to 
evaluate and fix rendering issues.