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Add forceSingleThreadedSkwasm option to Flutter web loader (#178406) #12712

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Add forceSingleThreadedSkwasm option to Flutter web loader (#178406) #12712

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Add forceSingleThreadedSkwasm option to Flutter web loader (#178406)
Ecraindrop Nov 18, 2025
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Fix line exceeding 80-character limit for semantic line breaks
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Fix doc comment line length and address prior style issues from previ…
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24 changes: 24 additions & 0 deletions src/content/platform-integration/web/initialization.md
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Expand Up @@ -126,11 +126,35 @@ The `config` argument is an object that can have the following optional fields:
|`entrypointBaseUrl`| The base URL of your Flutter app's entrypoint. Defaults to "/". |`String`|
|`hostElement`| HTML Element into which Flutter renders the app. When not set, Flutter web takes over the whole page. |`HtmlElement`|
|`renderer`| Specifies the [web renderer][web-renderers] for the current Flutter application, either `"canvaskit"` or `"skwasm"`. |`String`|
|`forceSingleThreadedSkwasm`| Forces the Skia WASM renderer to run in single-threaded mode for compatibility. |`bool`|

{:.table}

[web-renderers]: /platform-integration/web/renderers

## forceSingleThreadedSkwasm

A boolean flag to force the Skia WebAssembly (skwasm) renderer
to run in **single-threaded mode**. This is useful if:

- Your environment does not support multi-threaded WASM (for example,
`SharedArrayBuffer` is not available or required security
headers are missing).
- You want maximum browser compatibility.
- Use `false` (default) to allow multi-threaded rendering when
supported, which improves performance.

## Example usage

```js
_flutter.loader.load({
config: {
renderer: 'skwasm',
forceSingleThreadedSkwasm: true,
},
});
```

## Example: Customizing Flutter configuration based on URL query parameters

The following example shows a custom `flutter_bootstrap.js` that allows
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