source-level debugger

widget inspector that displays a visual widget tree,
and “widget select” mode where you select a widget
in the app and it drills down to that widget in
the tree

memory profiler

timeline view that supports tracing, and importing
and exporting trace information

logging view

If you run your application in debug mode or
profile mode, while it’s running you can open
DevTools in the browser to connect to your app.
DevTools doesn’t work well with an app compiled to
release mode, as the debugging and profiling
information has been stripped away.

If you use DevTools for profiling, make sure to
run your application in profile mode. Otherwise,
the main output that appears on your profile are the
debug asserts verifying the framework’s various invariants
(see Debug mode assertions).

For more information, see the
DevTools documentation.

Setting breakpoints