Flutter vs Kotlin: How to choose the right technology for your business app

In our previous article, we looked at Kotlin and explored why it has become one of the most important languages used in mobile application development in recent years. Kotlin combines a modern approach to programming, code safety and full integration with the Android ecosystem – so it is no surprise that it has gained such strong recognition among developers.

This naturally raises the question: is Kotlin always the best choice? Or are there projects where cross-platform technologies such as Flutter may prove to be a better solution?

If we want a new application to achieve commercial success, one of the key factors is reaching the widest possible audience. Today’s mobile device market is almost entirely divided between two competing operating systems – Android and iOS. This creates a significant challenge for software creators, who face a difficult decision. They can choose to build two separate native applications from scratch, which is a costly and time-consuming process, or they can give up their presence on one of the leading platforms – immediately losing access to a significant share of potential users and expected revenue.

This is one of the main reasons why cross-platform technologies have become increasingly popular. They promise the ability to create a single universal codebase for both systems. Although this sounds like an ideal solution in theory, reality is much more complex. How does it work in practice, and what are the main disadvantages and technical limitations of this type of approach?

What should you consider before choosing a technology?

One of the most important steps when selecting the right technology is conducting a thorough business analysis. For example, if we are creating an application for a country where Android devices are clearly dominant, a native approach based on Kotlin may prove to be the most reasonable choice. Why invest additional resources into developing a version for another operating system if it is unlikely to gain significant interest in a particular market?

It is equally important to precisely define what functionalities the application will include and determine its potential future development paths. Based on this, we can carefully analyse and compare the available technologies. It is worth checking whether they provide ready-made solutions for challenges that may appear throughout the development process. Another important factor is whether we can rely on community or vendor support when problems occur during development. It is also worth analysing which issues developers most commonly encounter in a given environment, so that we can avoid similar challenges ourselves. Additionally, we should consider the availability of experienced specialists on the market and how easy it will be to maintain the codebase in the long term. 

If we start developing an application and discover significant limitations during the process, changing the chosen technology may already be too late. Such a mistake can result in substantial financial costs and significantly extend the delivery timeline. Overlooking these risks at an early stage can lead to technical debt. Therefore, the initial technology decision is extremely important and directly affects the final success of the entire project.

What exactly is Flutter?

One of the most popular cross-platform technologies is Flutter – a development framework created and maintained by Google, designed to help developers efficiently build multi-platform applications. The first official version of this solution was released in 2017, and since then the project has been continuously and dynamically developed. Google is also responsible for the development of the Android operating system, which provides Flutter with a strong position on the market.

The main programming language used in Flutter is Dart. In many ways, it is similar to languages such as JavaScript, Java or C#, which means that developers with experience in these environments can relatively quickly start working with this technology.

How does Flutter work?

While most competing solutions rely on creating a special communication “bridge” between native UI components and cross-platform code, Flutter takes a completely different approach. It uses its own advanced rendering engine (initially Skia, while the modern Impeller engine is currently being introduced) and independently draws every single pixel on the screen. This works in a very similar way to advanced engines used in video games. Thanks to this approach, finished applications look exactly the same on every device while also delivering excellent speed, smoothness and performance.

One of the key and most appreciated features of the Flutter environment is the Hot Reload mechanism. After making changes to the source code, it allows developers to see the results almost instantly directly on the phone screen or emulator. The entire process happens automatically, without the need to restart the application or perform a time-consuming recompilation, significantly improving everyday development work.

The Flutter framework can also benefit from its independent rendering engine, which allows developers to quickly and efficiently create custom components, smooth animations and advanced transitions between screens. This makes it relatively easy to build visually attractive and modern user interfaces, helping the final product stand out from the competition. Additionally, separating the architecture from native system components ensures a consistent visual experience across different devices and operating systems.

Is Flutter the right technology for you?

Flutter works particularly well for smaller and less complex projects. It is often a great choice for startups and companies at an early stage of product development that want to bring their solution to market quickly and cost-effectively while reaching users across multiple platforms. 

One of the biggest advantages of this approach is the ability to maintain a single codebase for both Android and iOS. Compared to the traditional native development approach, this reduces the amount of development effort required, simplifies the process of introducing new features, and lowers application maintenance costs.

However, this does not mean that a multiplatform application can be built completely without additional effort. Each platform still has its own specific requirements, and some functionalities may require individual implementation. Nevertheless, using one technology for both systems significantly reduces code duplication and makes product development more efficient.

Flutter also eliminates some of the challenges associated with maintaining two separate applications. In a native approach, new features often need to be developed independently for Android and iOS, which can lead to differences between application versions. With Flutter, a large part of these changes can be delivered simultaneously across both platforms.

Another advantage of Flutter is its active community and extensive ecosystem of ready-made packages. Instead of building recurring components from scratch, developers can use existing solutions. This significantly reduces the time required to implement new functionalities, allowing teams to focus on unique business logic.

When should you consider a different solution than Flutter?

Despite its many advantages, Flutter is not the right choice for every project. One of the reasons is that it is not an official native technology for building mobile applications. As a result, the latest system updates and features are introduced first in the official programming languages supported by Google and Apple – Kotlin for Android and Swift for iOS.

Access to system features

If the key business goal of a project is rapid development and immediate access to the latest technological capabilities, a native application may be a better choice. To support the newest system features, Flutter developers often need to wait for updates to relevant libraries. In the case of slower-maintained packages, this may also create a risk of security vulnerabilities that could potentially be exploited.

When an application requires low-level access to system APIs, it may turn out that no existing library fully meets the project requirements. In such cases, developers need to write native code for both platforms, which significantly reduces one of Flutter’s main advantages – maintaining a shared codebase. A good example are advanced VOD applications, where support is required not only for smartphones but also for devices such as Android TV or Apple TV. Since Flutter does not provide official support for Apple TV, developers often need to rely on community-developed solutions. When implementing complex processes such as 4K streaming, DRM integrations, or support for specialised video codecs, resolving technical issues may become significantly more difficult.

User Experience

Flutter’s architecture, based on its own rendering engine, is both one of its greatest advantages and a potential limitation. It allows developers to create highly consistent visual experiences, but it also means that the interface does not directly use native system components. For most projects, this approach will not create any issues. However, in applications where the highest priority is achieving a fully native UX and behaviour, an approach based on Kotlin and Swift may be a better choice.

Ecosystem and availability of specialists

Choosing Flutter also means choosing the Dart programming language. Unlike React Native, which uses the widely adopted JavaScript and TypeScript ecosystems, or Kotlin, which is closely related to the highly popular Java ecosystem, Dart has a significantly smaller ecosystem focused almost exclusively on Flutter development.

The same applies to projects where uncompromising performance is the primary requirement. A well-optimised native application still has an advantage in tasks requiring intensive CPU processing.

What about… Kotlin Multiplatform?

We discussed Kotlin in our previous article – you can find it here.

Unlike traditional multiplatform frameworks, Kotlin Multiplatform does not aim to completely replace native technologies with a single shared layer. Its main goal is to enable developers to share the parts of an application where doing so provides the greatest value while maintaining access to native capabilities of each platform.

Flutter vs Kotlin Multiplatform

Flutter and Kotlin Multiplatform address a similar challenge – reducing the need to build two completely independent applications. However, they approach this goal in different ways.

Of course, there is no single technology that will be the perfect solution for every project. Flutter can be an excellent choice when the main priorities are fast product delivery, reduced initial costs, and the ability to develop an application simultaneously across multiple platforms. Kotlin Multiplatform, on the other hand, is particularly valuable in projects where flexibility, long-term development, and the ability to maintain a native approach where it brings the most value are essential. The final decision should always depend on the project’s characteristics, technical requirements, and business objectives.

Summary

Selecting the right technology is one of the most important decisions in the mobile application development process. It directly affects project costs, delivery time, and future scalability. It is a decision that influences the entire lifecycle of the application. When choosing between a multiplatform framework such as Flutter, Kotlin Multiplatform, or a traditional native approach based on Kotlin and Swift, it is essential to carefully analyse multiple factors and select the solution that best fits the specific project.

There is a reason why Flutter has gained enormous popularity in recent years. However, it is important to remember that native technologies still offer significant advantages. This is where Kotlin Multiplatform fits perfectly – especially when combined with Compose Multiplatform, it enables effective sharing of both business logic and user interface elements.

No universal tool that works perfectly in every situation exists. That is why technology decisions should be based on a thoughtful analysis rather than simply following trends. Understanding these differences is the foundation of an effective mobile strategy, while choosing the right tools from the beginning helps avoid frustration and costly changes in the future.

At Infinity Group, we design and develop mobile applications by selecting technologies based on our clients’ actual business needs and long-term goals. If you are wondering which solution will be the best fit for your project, let’s talk. We will help you evaluate which approach best supports your business objectives and provides the right balance between costs, delivery time, and future development opportunities.