Flutter is the open-source framework created by Google to build applications that run on iOS, Android, web and desktop from a single codebase. You write in Dart, and the code is compiled to native code for each platform. The difference from older hybrid frameworks is substantial: Flutter does not use the system browser to render the interface, it draws every element with its own graphics engine. The result is an app that behaves identically on every device, with performance close to a native one.
This guide covers how it actually works, its concrete benefits and limits, how it differs from React Native and native development and — above all — when it is the right choice for a business app. What follows comes from the experience of Codebaker, a Bologna-based software house that builds apps in Flutter, React Native and native Swift/Kotlin, and picks the technology from the project requirements rather than by default.
How Flutter works
To understand what Flutter is, it helps to look at the three pieces it is made of, because each one explains one of its characteristics.
The Dart language
Dart is a typed, object-oriented language with a syntax familiar to anyone who knows Java, C# or TypeScript. It has two compilation modes: Ahead-of-Time to native machine code for production builds — where the performance comes from — and Just-in-Time during development, which is what makes hot reload possible: change the code and see the result on the device in under a second, without a full rebuild. In day-to-day project work this shortens review cycles considerably, because a visual change can be demonstrated during the meeting itself.
The rendering engine
This is the architectural choice that sets Flutter apart from almost every other cross-platform framework. Instead of asking the operating system to draw a button or a list, Flutter draws every pixel directly. The upside is an interface that is identical and predictable on any device and OS version, without the rendering differences that force constant fixes. The price is that the engine ships inside the app, which increases its size.
Widgets
In Flutter everything is a widget: a piece of text, a margin, a button, an entire screen. They nest inside one another like building blocks to form any interface. When you need device-specific features — camera, GPS, Bluetooth, NFC reader — you use plugins, which bridge to the native iOS and Android code. This is where a Flutter project can still call for native skills, and it is worth checking before you start.
Benefits and limits of Flutter
No framework is right in the abstract. These are the benefits and limits that actually matter when evaluating Flutter for a business project.
| Benefits | Limits |
|---|---|
| A single codebase for iOS and Android: less development time and, above all, one codebase to maintain | Larger app than an equivalent native one, because it bundles the rendering engine |
| An interface that is identical and predictable on every device | New iOS and Android features arrive later than in the official SDKs |
| Strong performance thanks to compilation to native code | Specific hardware features may still require native code |
| Hot reload: much faster review cycles | A smaller ecosystem than JavaScript's |
Flutter, React Native or native: the differences
Flutter and React Native solve the same problem two different ways. Flutter uses Dart and draws the UI with its own engine: rendering is identical everywhere and control over the look is total. React Native uses JavaScript and React and calls the real native components of the operating system: the app takes on the typical look of the platform it runs on. In practice Flutter fits when you need a polished interface that is consistent everywhere, or complex graphics; React Native fits when the team already knows React and wants to share logic with a web application.
Native development (Swift for iOS, Kotlin for Android) remains the best choice when you need extreme performance, heavy use of platform features or immediate access to new OS capabilities — at the cost of two separate codebases and two teams with distinct skills. We compared all three routes in detail, with a comparison table and real cases, in our article on React Native, Flutter or native development.
When Flutter fits a business app
Flutter is the most efficient choice when the app has to run on iOS and Android with the same features, when the budget does not justify two separate native builds and when you need to reach production quickly without giving up a polished interface. It also works well in industrial scenarios that require offline operation and communication with hardware.
A concrete example: for Piusi B.SMART we built a Flutter app that communicates over Bluetooth Low Energy with fuel dispensing units, works offline and is used by around 10,000 people a day. The Bluetooth interface alone took roughly four months of dedicated work — a useful reminder that, under demanding hardware requirements, implementation quality weighs more than the choice of framework.
Native is worth considering instead when the app makes heavy use of platform-specific features, or when adopting new iOS and Android capabilities immediately is a requirement. For Conor, for instance, we chose native iOS and Android apps integrated in real time with the AS400 ERP.
Frequently asked questions about Flutter
Which language does Flutter use?
Dart, a typed, object-oriented language developed by Google, with a syntax familiar to anyone who knows Java, C# or TypeScript. It is not as widespread as JavaScript, but it is straightforward for an experienced developer to pick up: the real learning curve is Flutter's widget model rather than the language itself.
Is Flutter suitable for complex business applications?
Yes. It is not limited to prototypes and MVPs: it runs in production in applications with many screens, offline data handling, synchronisation with ERP systems and hardware communication. The Piusi B.SMART app is a direct example.
Is Flutter free?
Yes, Flutter is open source under a BSD licence: there are no licence fees or royalties. A project's costs are analysis, development, store publishing and maintenance — exactly as with any other technology.
Considering Flutter for your app?
If you have an app to build and want to know whether Flutter is the right technology, tell us the requirements: the choice comes from the real constraints of the project, not from the framework of the moment. See how we work on Flutter app development and on custom business apps, or get in touch for a free consultation.