docs: Default Splash / Loading screen for web app in index.html (flutter#177084)

Gustl22 · web-flow · commit bf4957815e10 · 2025-11-03T15:21:21.000Z
Contributes to flutter#102178 First I wanted to cherry-pick flutter/gallery#630. But then I noticed that there already exists a documentation: https://docs.flutter.dev/platform-integration/web/initialization. As most users won't expect this to be customizable (as myself), I wrote a little docs in the index.html.tmpl that link to this page. https://docs.flutter.dev/platform-integration/web/initialization#example-display-a-progress-indicator I still think a default splash screen should be in place, e.g. by providing the `flutter_bootstrap.js` by default (?) ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [ ] I updated/added relevant documentation (doc comments with `///`). - [ ] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [ ] All existing and new tests are passing. If you need help, consider asking for advice on the #hackers-new channel on [Discord].  [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md
diff --git a/packages/flutter_tools/templates/app/web/index.html.tmpl b/packages/flutter_tools/templates/app/web/index.html.tmpl
@@ -33,6 +33,14 @@
   <link rel="manifest" href="manifest.json">
 </head>
 <body>
+  <!--
+    You can customize the "flutter_bootstrap.js" script.
+    This is useful to provide a custom configuration to the Flutter loader
+    or to give the user feedback during the initialization process.
+
+    For more details:
+    * https://docs.flutter.dev/platform-integration/web/initialization
+  -->
   <script src="flutter_bootstrap.js" async></script>
 </body>
 </html>
