I can't start the Dart Dev Tools in VS Code, when I launch in debugging mode it opens a chrome window says Connect to a running app Enter a port or URL to a running Dart or Flutter application.

When I hover over the Dart DevTools button, it shows a port but I still can't connect to it.

Any ideas?


Solution 1: Hayeong Choi

Start your flutter app with --observatory-port option. For example,

flutter run --observatory-port=9200

Once the app starts, you’ll see a message in your terminal that looks like:

An Observatory debugger and profiler on Android SDK built for x86 is available at: http://127.0.0.1:9200/Swm0bjIe0ks=/

Paste the URL you got from running your app (http://127.0.0.1:9200/Swm0bjIe0ks=/) into the connect dialog to connect your app to DevTools.

Hope this helps.


Solution 2: Uri Goo

In Run flutter in Terminal with port you want. It can 9200 or 9300 or 9301 etc flutter run --observatory-port=9200

On the logcat you will see message look like "An Observatory debugger and profiler on Android SDK built for x86 is available at: http://127.0.0.1:9200/Swm0bjIe0ks=/"

After that copy and past url (http://127.0.0.1:9200/Swm0bjIe0ks=/) to dialog connect your app to DevTools


Solution 3: ROB

In my case the above answers did not work due I had another problem: PATH: the enviroment variables. This was because I couldn't execute flutter command in the terminal at my folder app project , so enviroment variables at system level it's necessary and I was doing this at user level for Windows. So I run flutter doctor o whatever to see if alredy the path was working and then I used the answer of @Hayeong Choi.


Solution 4: Abhishek Sharma

Hi run your app on emulator or real device. On bottom of android studio you will find a run tab on run tab there will be a message like below: Debug service listening on ws://127.0.0.1:54675/CPu_ErpGRaw=/ws

copy (ws://127.0.0.1:54675/CPu_ErpGRaw=/ws) and paste it on Dart DevTools input field. It will be connected to your running device or emulator


Solution 5: Fathi Dev

On Visual Studio Code: click the letter (v) while the app is running. that's it!