DevTools

What is DevTools?

DevTools is a suite of performance and debugging tools for Dart and Flutter.

What can I do with DevTools?

Here are some of the things you can do with DevTools:

• Inspect the UI layout and state of a Flutter app.
• Diagnose UI jank performance issues in a Flutter app.
• CPU profiling for a Flutter or Dart app.
• Network profiling for a Flutter app.
• Source-level debugging of a Flutter or Dart app.
• Debug memory issues in a Flutter or Dart command-line app.
• View general log and diagnostics information about a running Flutter or Dart command-line app.
• Analyze code and app size.

We expect you to use DevTools in conjunction with your existing IDE or command-line based development workflow.

How do I install DevTools?

See the VS Code, Android Studio/IntelliJ, or command line pages for installation instructions.

Troubleshooting some standard issues

Question: My app looks janky or stutters. How do I fix it?

Answer: Performance issues can cause UI frames to be janky and/or slow down some operations.

1. To detect which code impacts concrete late frames, start at Performance > Timeline.
2. To learn which code takes the most CPU time in the background, use the CPU profiler.

For more information, check out the Performance page.

Question: I see a lot of garbage collection (GC) events occurring. Is this a problem?

Answer: Frequent GC events might display on the DevTools > Memory > Memory chart. In most cases, it’s not a problem.

If your app has frequent background activity with some idle time, Flutter might use that opportunity to collect the created objects without performance impact.

Providing feedback

Please give DevTools a try, provide feedback, and file issues in the DevTools issue tracker. Thanks!

Other resources

For more information on debugging and profiling Flutter apps, see the Debugging page and, in particular, its list of other resources.

For more information on using DevTools with Dart command-line apps, see the DevTools documentation on dart.dev.