Flutter Web: --no-sandbox flag prevents Chrome/Edge launch on Windows

[benedicte69]

I encountered an issue when trying to run a Flutter web app with:
flutter run -d chrome
flutter run -d edge
Both commands fail because Flutter attempts to launch the browser with the --no-sandbox flag. In my Windows environment, this flag is blocked or considered unsafe, so the browser does not start at all.

Steps to Reproduce

On Windows, run flutter run -d chrome or flutter run -d edge.

Observe that the browser fails to launch due to --no-sandbox.

Expected Behavior The browser should launch normally without requiring the --no-sandbox flag, or there should be a way to configure Flutter to skip this flag.

Actual Behavior The app fails to open because the browser refuses to start with --no-sandbox.

Environment windows 11

Flutter 3.38.3 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 19074d1 (4 days ago) • 2025-11-20 17:53:13 -0500
Engine • hash 8bf2090718fea3655f466049a757f823898f0ad1 (revision 13e6587) (4 days ago) • 2025-11-20 20:19:23.000Z
Tools • Dart 3.10.1 • DevTools 2.51.1

Android Studio Otter | 2025.2.1 Patch 1
Build #AI-252.25557.131.2521.14432022, built on November 13, 2025
Runtime version: 21.0.8+-14196175-b1038.72 amd64
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.

Additional Notes As a workaround, I can use flutter run -d web-server and open the URL manually, but this prevents DevTools from attaching automatically.

Suggested Improvement It would be helpful if Flutter:

Allowed disabling --no-sandbox via a configuration option (e.g. flutter run -d chrome --no-sandbox=false), or

Automatically detected when the flag is unsafe on Windows and skipped it.

This would make the developer experience smoother and avoid manual workarounds.

Thank you for considering this improvement!
Thank you for your support and for considering this issue.

[tirth-patel-nc]

Appears to be a duplicate of #171436. See #171436 (comment) if it helps your case further.

[benedicte69]

Thanks for your quick answer but unfortunatly it does not help.

The issue is not Chrome, Edge, or Windows itself, but the --no-sandbox flag that Flutter adds when launching browsers. On Windows this flag is treated as unsafe, which prevents the browser from starting at all.

Running Chrome/Edge with administrator privileges may appear to “work,”#171436 but it is not a viable solution:

It introduces obvious security risks (browser inherits full system privileges).

It can corrupt user profiles (ACLs, cache, extensions).

It hides the bug instead of fixing it.

The real fix would be for Flutter to:

Detect when --no-sandbox is blocked on Windows and skip adding it.

Or provide an explicit option to disable it (--no-sandbox=false).

see line 242 flutter\packages\flutter_tools\lib\src\web\chrome.dart

`    final int port = debugPort ?? await _operatingSystemUtils.findFreePort();
    final args = <String>[
      chromeExecutable,
      // Using a tmp directory ensures that a new instance of chrome launches
      // allowing for the remote debug port to be enabled.
      '--user-data-dir=${userDataDir.path}',
      '--remote-debugging-port=$port',
      // When the DevTools has focus we don't want to slow down the application.
      '--disable-background-timer-throttling',
      // Since we are using a temp profile, disable features that slow the
      // Chrome launch.
      '--disable-extensions',
      '--disable-popup-blocking',
      '--bwsi',
      '--no-first-run',
      '--no-default-browser-check',
      '--disable-default-apps',
      '--disable-translate',

      // Remove the search engine choice screen. It's irrelevant for app
      // debugging purposes.
      // See: https://github.com/flutter/flutter/issues/153928
      '--disable-search-engine-choice-screen',
      '--no-sandbox',

      if (headless) ...<String>['--headless', '--disable-gpu', '--window-size=2400,1800'],
      ...webBrowserFlags,
      url,`

[benedicte69]

Nevertheless, I should add a correction: It actually works if Android Studio is run in non‑admin mode. Running the IDE as administrator causes Chrome/Edge to inherit elevated privileges, which prevents them from reading the normal user-data-dir and triggers the --no-sandbox failure.

So the "recommended" practice is:

Run Android Studio as a normal user.

Keep browsers in user mode.

Avoid the “admin workaround,” which only hides the bug and introduces security risks.

BUT Be aware that disabling the sandbox (--no-sandbox) itself is insecure: the sandbox is a core browser protection, and removing it exposes the system to potential exploits.

Therefore, the ideal outcome would be for Flutter tooling to provide a proper fix — either by detecting when --no-sandbox is unsafe on Windows and skipping it, or by offering a configuration option to disable it safely.

Note: flutter run -d chrome can work in non‑admin mode, but flutter run -d edge still fails on Windows. This shows the issue is deeper than just admin privileges and requires a tooling fix.

[benedicte69]

Please bring the fix for -d edge into stable, and make it a permanent solution so Edge runs securely.

[tirth-patel-nc]

@benedicte69 are you getting the same behaviour on latest master as well?

[benedicte69]

latest master channel result: using android studio not in admin mode ,

---

In android studio CMD flutter run -d edge

flutter --version
Flutter 3.39.0-1.0.pre-322 • channel master • https://github.com/flutter/flutter.git
Framework • revision 0b191ba (11 hours ago) • 2025-11-26 15:00:42 -0800
Engine • hash 7d052bbcab602be7f2dadad5130ff12a66d1f755 (revision c70e825) (7 hours ago) • 2025-11-26 22:56:58.000Z
Tools • Dart 3.11.0 (build 3.11.0-173.0.dev) • DevTools 2.52.0
PS (*******)\test02noadminasedge> flutter run -d edge
Resolving dependencies...
Downloading packages...
characters 1.4.0 (1.4.1 available)
Got dependencies!
1 package has newer versions incompatible with dependency constraints.
Try flutter pub outdated for more information.
Launching lib\main.dart on Edge in debug mode...
Waiting for connection from debug service on Edge... 24,9s

Flutter run key commands.
r Hot reload.
R Hot restart.
h List all available interactive commands.
d Detach (terminate "flutter run" but leave application running).
c Clear the screen
q Quit (terminate the application on the device).

This app is linked to the debug service: ws://127.0.0.1:61940/ntv7jhKgetU=/ws
Debug service listening on ws://127.0.0.1:61940/ntv7jhKgetU=/ws
A Dart VM Service on Edge is available at: http://127.0.0.1:61940/ntv7jhKgetU=
The Flutter DevTools debugger and profiler on Edge is available at:
http://127.0.0.1:61940/ntv7jhKgetU=/devtools/?uri=ws://127.0.0.1:61940/ntv7jhKgetU=/ws
Starting application from main method in: org-dartlang-app:/web_entrypoint.dart.

---

with android studio button

[ +10 ms] <- compile org-dartlang-app:/web_entrypoint.dart
[{"event":"app.progress","params":{"appId":"7bab58be-7396-4e44-aa6c-521c3c9bf90c","id":"0","progressId":null,"finished":true}}]
[+19748 ms] Synced 68.4MB.
[ +1 ms] <- accept
[ ] Caching compiled dill
[ +165 ms] Launching Chromium (url = http://localhost:63500, headless = false, skipCheck = false, debugPort = null)
[ ] Will use Chromium executable at C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
[ +213 ms] [CHROME]: [12448:9800:1127/111229.956:ERROR:components\edge_ess\vbs_encoder.cc:100] LoadEnclaveImageW failed, error code 577
[ +82 ms] [CHROME]:
[ ] [CHROME]: DevTools listening on ws://127.0.0.1:63513/devtools/browser/b9f92e8f-b467-4555-8f2b-c3b97cef1acd
[{"event":"app.webLaunchUrl","params":{"url":"http://localhost:63500","launched":true}}]
[{"event":"app.started","params":{"appId":"7bab58be-7396-4e44-aa6c-521c3c9bf90c"}}]
[+4212 ms] DwdsInjector: Received request for entrypoint at http://localhost:63500/main_module.bootstrap.js
[ +3 ms] MetadataProvider: Loading debug metadata...
[ +3 ms] MetadataProvider: Loaded debug metadata for module: web_entrypoint.dart
[ ] MetadataProvider: Loaded debug metadata for module: web_plugin_registrant.dart

[ ] A Dart VM Service on Edge is available at: http://127.0.0.1:49234/ZialKYlwcEI=
[ +1 ms] The Flutter DevTools debugger and profiler on Edge is available at: http://127.0.0.1:9100?uri=ws://127.0.0.1:49234/ZialKYlwcEI=/ws
Debug service listening on ws://127.0.0.1:49234/ZialKYlwcEI=/ws
[{"event":"app.debugPort","params":{"appId":"7bab58be-7396-4e44-aa6c-521c3c9bf90c","port":49234,"wsUri":"ws://127.0.0.1:49234/ZialKYlwcEI=/ws"}}]
[{"event":"app.devTools","params":{"appId":"7bab58be-7396-4e44-aa6c-521c3c9bf90c","uri":"http://127.0.0.1:9100?uri=ws://127.0.0.1:49234/ZialKYlwcEI=/ws"}}]
[{"event":"app.dtd","params":{"appId":"7bab58be-7396-4e44-aa6c-521c3c9bf90c","uri":"ws://127.0.0.1:49233/vmuEOHvB6Vk="}}]
[ +86 ms] DevHandler: VmService proxy responded with an error:
{jsonrpc: 2.0, id: 18, error: {code: -32601, message: Method not found, data: {jsonrpc: 2.0, method: _setStreamIncludePrivateMembers, id: 18, params: {streamId: Debug, includePrivateMembers: false}}}}
[ +1 ms] DevHandler: VmService proxy responded with an error:
{jsonrpc: 2.0, id: 20, error: {code: -32602, message: The stream ToolEvent is not supported on web devices}}
[ ] DevHandler: VmService proxy responded with an error:
{jsonrpc: 2.0, id: 21, error: {code: -32601, message: Method not found, data: {jsonrpc: 2.0, method: _setStreamIncludePrivateMembers, id: 21, params: {streamId: Extension, includePrivateMembers: false}}}}
[ ] DevHandler: VmService proxy responded with an error:
{jsonrpc: 2.0, id: 22, error: {code: -32601, message: Method not found, data: {jsonrpc: 2.0, method: _setStreamIncludePrivateMembers, id: 22, params: {streamId: Logging, includePrivateMembers: false}}}}
[ ] DevHandler: VmService proxy responded with an error:
{jsonrpc: 2.0, id: 23, error: {code: -32601, message: Method not found, data: {jsonrpc: 2.0, method: _setStreamIncludePrivateMembers, id: 23, params: {streamId: Service, includePrivateMembers: false}}}}
[ +1 ms] DevHandler: VmService proxy responded with an error:
{jsonrpc: 2.0, id: 25, error: {code: -32601, message: Method not found, data: {jsonrpc: 2.0, method: _setStreamIncludePrivateMembers, id: 25, params: {streamId: Isolate, includePrivateMembers: false}}}}
[ +628 ms] Starting application from main method in: org-dartlang-app:/web_entrypoint.dart.

[benedicte69]

so it seems to work that way in master channel

`    final int port = debugPort ?? await _operatingSystemUtils.findFreePort();
    final args = <String>[
      chromeExecutable,
      // Using a tmp directory ensures that a new instance of chrome launches
      // allowing for the remote debug port to be enabled.
      '--user-data-dir=${userDataDir.path}',
      '--remote-debugging-port=$port',
      // When the DevTools has focus we don't want to slow down the application.
      '--disable-background-timer-throttling',
      // Since we are using a temp profile, disable features that slow the
      // Chrome launch.
      '--disable-extensions',
      '--disable-popup-blocking',
      '--bwsi',
      '--no-first-run',
      '--no-default-browser-check',
      '--disable-default-apps',
      '--disable-translate',

      // Remove the search engine choice screen. It's irrelevant for app
      // debugging purposes.
      // See: https://github.com/flutter/flutter/issues/153928
      '--disable-search-engine-choice-screen',

      if (headless) ...<String>[
        '--no-sandbox',
        '--headless',
        '--disable-gpu',
        '--window-size=2400,1800',
      ],
      ...webBrowserFlags,
      url,
    ];`

[tirth-patel-nc]

so it works fine on master, just to confirm?

[benedicte69]

yes I confirm that in master channel it opens the app in the browers (both -d edge and -d chrome) in quitte a more secure way since it creates a distinct profile.

// Remove the search engine choice screen. It's irrelevant for app
// debugging purposes.
// See: #153928
'--disable-search-engine-choice-screen',

  **if (headless) ...<String>[
    '--no-sandbox',
    '--headless',
    '--disable-gpu',
    '--window-size=2400,1800',
  ],
  ...webBrowserFlags,
  url,
];**