Google Flutter 2.5 UI kit is now stable

Flutter 2.5, the latest version of Google’s UI toolkit for native app development, offers better performance and full-screen enhancements for Android.

Released on September 8, Flutter 2.5 improves frame rasterization by wiring the shader precompile through the Metal rendering. Proponents of Flutter emphasized this move as another step toward lowering the jank of iOS. Additionally, frame processing now takes precedence over other asynchronous event processing, eliminating jank from this source in Flutter tests. An additional move to reduce the jank involves the garbage collector (GC), which has suffered a jank when the GC pauses the UI thread to reclaim memory; memory for unused images is now enthusiastically reclaimed, significantly reducing GCs.

Another performance improvement involves latency when sending messages between Dart and Objective-C / Swift (iOS) or Dart and Kotlin / Android. As part of optimizing message channels, removing unnecessary copies of messaging codecs reduces latencies by up to 50%, depending on the size of the message and the device.

Another performance improvement concerns targeting to iOS. Flutter apps built on Apple Silicon M1 Macs run natively on ARM iOS simulators. Therefore, there is no Rosetta translation between the Intel x86_64 and ARM instructions, which increases performance during testing of iOS applications and allows developers to avoid subtle Rosetta issues. This is a step on the way to full Flutter compatibility for Apple Silicon.

Flutter 2.5 was announced as stable on September 8. Installation instructions can be found at Also in Flutter 2.5:

  • For Android, issues related to full screen modes have been fixed. Support is provided for various full screen modes, which affect the visibility of UI overlays, such as status and bottom navigation bars.
  • Dart 2.14, also unveiled on September 8, is included, introducing a new format to make waterfalls clearer, new pub support for ignoring files, and language features, including the return of the legendary triple shift operator. Also included in Dart 2.14 is a standard set of fluff shared between new Dart and Flutter projects right out of the box.
  • Flutter DevTools can take advantage of updates that allow, for example, Flutter to do a better job of associating trace events with specific frameworks, helping developers determine why a framework might be over budget. DevTools also helps diagnose shader build problems in an application, using the Flutter engine’s ability to identify shader build events. Meanwhile, an update to the Widget Inspector lets you hover over a widget to evaluate the object and view properties.
  • Support for iOS 8 is being dropped, with Google citing its low market share.

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