Flutter is Google’s new open source technology for creating native Android and iOS apps with a single codebase. Unlike other popular solutions, Flutter is not a framework; it’s a complete SDK – software development kit – which already contains everything you will need to build cross-platform applications. This includes a rendering engine, ready-made widgets, testing and integration APIs, and command-line tools.
Similar technologies such as Xamarin, React Native, Ionic, or NativeScript all try to achieve platform nativeness via different approaches. We’ve written a whole article comparing these cross-platform tools. Now, let’s see what Flutter introduces to the game.
Flutter follows the reactive development architecture, but with a twist. The main thing to know about reactive programming is that it updates UI contents automatically when you update the variables in the code. React Native also follows this principle, but it uses the JavaScript bridge to access OEM widgets. But since the app has to pass this bridge to access widgets each time, it causes performance issues. Flutter, however, omits this bridge altogether and communicates with the native platform using Dart.
Dart is Flutter’s object-oriented language that uses Ahead-of-Time compilation techniques and compiles into native code without that additional bridge. This noticeably speeds up the app startup time. Besides, Flutter doesn’t have to call to OEM (original equipment manufacturer) widgets, because it uses its own. As seen on the image below, Flutter uses the OS as a canvas to build an interface on and moves services such as gestures, rendering, and animations into the framework itself, which gives developers complete control over the system.