Flitter, flutter, fly!

Flutter beta 1: For beautiful cross-platform app development

Jane Elizabeth
© Shutterstock / StudioSuzyB FotoGrafix

Google’s new mobile UI framework Flutter SDK is now in beta! What can we expect from it? Beautiful cross-platform app development and super-fast performance, of course.

Google is at it again with their A/B testing. Despite the runaway success of their mobile SDK Android, they’re not resting easily on their laurels. And so, we now have Flutter, a lovely mix of React and Dart.

The alpha version of Flutter was released last year; after months of development, the first beta release of Flutter is going live as part of Mobile World Congress 2018.

Flutter is a mobile UI framework intended to help developers create high-quality native interfaces on both iOS and Android. Flutter is free and open source, just like the Android SDK, and works with already existing code. Some of the more notable users of Flutter include Hamilton: The Musical and Google’s own multibillion dollar ad platform, AdWords.

SEE MORE: Dart 2 brings major changes to improve client-side development

So how does it work?

The main draw to Flutter is its clever and speedy mobile development for both iOS and Android. For one thing, it neatly sidesteps cross-platform problems by ignoring their frameworks. Flutter apps run on the Flutter rendering engine, which is written in C++, and the Flutter Framework, which is written in Dart. These are both included and bundled into every app, which obviates the need to directly compile to native Android or iOS. The SDK itself compiles a compatible app that runs natively on whatever ecosystem it is in.

Including both a rendering engine and framework does increase the install size. According to the Flutter FAQ, an “empty” app runs around 6.7MB on Android. However, with that additional footprint, developers gain an incredibly fast app that is designed to hit 60FPS, a considerable improvement for Android developers. Plus, Android’s fragmentation issues aren’t a problem because you ship the platform as part and parcel of the app.

SEE MORE: Flutter: A beautiful mix of React and Dart for mobile SDK


Since the alpha release last June, Flutter has improved tools and features considerably. With input from the community, Flutter has developed a number of new features including:

  • screen reader support and other accessibility features
  • right-to-left text
  • localization and internationalization
  • iPhone X and iOS 11 support
  • inline video
  • additional image format support
  • running Flutter code in the background
  • and much more.

This mobile SDK is designed to be helpful for developers from all background. The composible widget sets and rich animation libraries make it easy to create expressive and flexible designs. Increased support for Android Studio and Visual Studio Code for Dart provides tools for effectively editing, refactoring, running, and reloading Flutter mobile apps, and AngularDart web apps.

There are also new refactorings to help developers manage their widget code as well as a new widget inspector to help them browse the widget tree.


Flutter’s widget inspector.

Unsurprisingly, Flutter’s beta also works with a pre-release of Dart 2. We talked about Dart 2’s new features yesterday, which include improved support for declaring UI in code. Dart 2 removes a lot of unnecessary code for developers who are building their own UI.

SEE MORE: AngularDart 4.0 adds preliminary support for component inheritance and more

Getting Flutter

Flutter is still a beta release, so they’re working all the bugs out of the system. That being said, it’s a stable enough release that it’s being used by Google for a multibillion dollar ad-platform. So, you can probably give it the benefit of the doubt.

Flutter is available here for Windows, Mac, and Linux. It’s also available via GitHub. If you’re interested in contributing to the SDK, all help is welcome here.

Jane Elizabeth
Jane Elizabeth is an assistant editor for

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