What is this?
This is a companion repo to the main Flutter repo. It contains the source code for a suite of performance tools for Dart and Flutter.
Trying it out
Currently, the best way to try DevTools out is by running it as a pub globally activated package.
If you have
pub on your path, you can run:
pub global activate devtools
If you have
flutter on your path, you can run:
flutter packages pub global activate devtools
That will install (or update) DevTools on your machine.
Going forward, we expect to have additional (and easier!) distributions mechanisms for DevTools.
Run the DevTools application server
Next, run the local web server, which will serve the DevTools application itself.
Run one of the following two commands:
pub global run devtools(if you have
pubon your path)
flutter packages pub global run devtools(if you have
flutteron your path)
On the command-line, you should see output that looks something like:
Serving DevTools at http://127.0.0.1:9100
Start an application to debug
Next, start an app to connect to. This can be either a Flutter application or a Dart command-line application. The example below uses a Flutter app.
- and, run
flutter run --observatory-port=9200
You'll need to have a device connected or a simulator open for
flutter run to work. Once the app
starts up, you'll be able to connect to it from devtools.
Open DevTools and connect to the target app
Using DevTools now is as simple as opening a local browser window and pointing the DevTools app to the running Flutter application. If you used the same ports as the example above, you can open:
This can also be done via the command line with
open http://localhost:9100/?port=9200. The first port
in the url is for the local server that is serving the DevTools web UI. The second port is to tell
DevTools itself which local app to connect to for debugging and inspection.
Feedback and issues are best reported at https://github.com/flutter/devtools/issues. Thanks for trying out DevTools!