Flutter News August 2026 (2/2)

1. Flutter 3.47: Material and Cupertino move out of the SDK

Flutter 3.47 landed on August 12 carrying the framework's biggest structural change in years. The material_ui and cupertino_ui packages hit version 1.0 on pub.dev, cutting the design systems loose from the core SDK. Until now Material and Cupertino could only ship with the framework's quarterly release; as standalone packages they can ship weekly. Both libraries remain bundled in the core SDK for this cycle and existing imports don't yet produce deprecation warnings — formal deprecation is scheduled for the November release. Running dart fix --apply --code=migrate_design_widgets rewrites your imports, and MaterialUiCompatibilityBridge lets old-style bundled imports and the new standalone packages coexist in one dependency graph while your dependencies catch up. The flutter_localizations package has been unbundled at the same time — localization delegates now live inside the respective design packages.

The other half of the release is about rendering and Apple platforms. Impeller is now the default renderer on macOS, Windows and Linux, with Wide Gamut Color enabled by default on macOS, and the option to fall back to Skia on desktop will disappear in upcoming releases. Minimum deployment targets rose from iOS 13 to 15 and macOS 10.15 to 12 in preparation for Xcode 27 — and note that apps built with Xcode 27 that have not adopted the UIScene lifecycle will fail to launch. Widget Previews reached stable with local build caching and PreviewThemeData, desktop gained popup windows on Linux and Windows plus flavor support, and the web got experimental deferred loading for Wasm via --enable-wasm-deferred-loading.

Source: Flutter Blog — What's new in Flutter 3.47, Aug 2026

2. Dart 3.13: primary constructors go stable

Dart 3.13 shipped the same day as Flutter 3.47, and its theme is brevity. Primary constructors, still an experiment in Dart 3.12, are now stable — field declarations and the main constructor fit on a single line, as in class Point(final int x, final int y);. No more spelling out every field three times: once in the declaration, once as a constructor parameter, once in the assignment. Six new lints enforce a consistent style around them, and four new IDE refactorings automate converting existing classes.

Performance moved too. The @RecordUse annotation enables tree-shaking of unused native code in FFI bindings, which can substantially shrink shipped binaries, while WebAssembly deferred loading in preview cuts the initial load time of large web apps. dart format fixed misformatted method calls and now separates import sections with a blank line per Effective Dart. On pub.dev, <callout-box> tags and the {@example} directive arrived, the latter pulling code snippets straight out of files in example/ into your API docs.

Source: Dart Blog — Announcing Dart 3.13, Aug 2026

3. Two hotfixes: Flutter 3.47.1 and 3.47.2

The new line needed two hotfixes within a fortnight. Version 3.47.1 arrived on August 19 with Dart SDK 3.13.1 and eleven fixes, all in tooling and embedders — no framework API changed. It restored hot restart for WASM web builds, killed a SwiftPM race condition that broke parallel multi-target iOS/macOS builds with a FileSystemException, fixed PathNotFoundException crashes during concurrent native-asset cleanup, corrected ADB device-list parsing for wireless mDNS serials, and stopped impellerc crashing on paths containing Unicode. Plugin validation was also hardened to prevent arbitrary code being injected into GeneratedPluginRegistrant.

Version 3.47.2 followed on August 25 with fourteen fixes and one security item: an update to the bundled libpng. Among the rest, SwiftPM got another round of attention — this time failing iOS and macOS builds and integration into existing native iOS apps under Xcode 27 — alongside a memory leak in Linux touch-event handling, an external-texture crash on Windows, truncated hot reload timestamps on Windows, and screen reader header announcements on Linux. If you have already moved to 3.47, there's no reason to put this upgrade off.

Source: flutter/flutter — CHANGELOG, Aug 2026