Google pulls the wraps off Flutter, Dart upgrades Google pulls the wraps off Flutter, Dart upgrades Flutter 2 native UI toolkit debuts production-quality support for the web, while Dart 2.12 adds sound null safety Credit: Google Google's Flutter UI toolkit and companion Dart language have both received upgrades this month, with Flutter 2 moving web support from beta to stable and Dart 2.12 adding null safety. An open source UI toolkit for building natively compiled apps for multiple operating systems and form factors, Flutter now includes the web among the supported platforms. Google said three scenarios are critical to Flutter web support: Progressive web apps (PWA), combining the web with desktop app capabilities.