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Dart 4 & WasmGC: The Foundation

Flutter 2026: The Impeller & Wasm Masterclass

Understanding Dart 4 & WasmGC

WebAssembly used to struggle with Garbage Collection (GC). In 2026, WasmGC is native in all browsers.

Key Changes

  • Direct Mapping: Dart objects now map directly to WasmGC heap objects.
  • No JS Bridge: Zero-latency communication between Dart and the browser APIs.

Code Example

Compile your first Wasm app: bash flutter build web --wasm

This produces a .wasm file that is 40% smaller and 2x faster than the old JS-compiled apps.