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Flutter vs Kotlin:
similarities, key differences & use cases
February 5, 2026
The Flutter vs Kotlin choice arises often since the two technologies are commonly used for building cross-platform apps. However, significant differences in their underlying development stacks and app-creation approaches make each more appropriate for specific project needs.
Backed by solid experience in both Kotlin and Flutter development, Itransition helps companies choose technologies that best fit their project needs and use them to implement robust, feature-rich applications that operate smoothly and consistently across devices and platforms.
Flutter overview
Flutter is an open-source app development framework for building user interfaces (UI) for applications that operate on mobile, web, and desktop platforms and have a single codebase. It was released by Google in 2018 with the initial support of Android and iOS apps, but as the framework evolved, the scope of supported platforms has expanded and now also includes web and desktop (Windows, macOS, Linux). Today, Flutter is popular due to its powerful software development kit (SDK) and features that help shorten the development time and improve developers’ productivity while enabling the creation of high-performing, visually rich applications.
Key features
Flutter uses Dart, a modern general-purpose programming language developed by Google. Dart has a concise, expressive syntax that reduces boilerplate code and makes app code easier to read and maintain, along with powerful features like strong and static typing and null safety. The language comes with a wide collection of libraries that help streamline many routine development tasks, like writing code for data management and handling asynchronous operations. In released Flutter apps, the Dart code is compiled into native code that devices can run directly, delivering the same smooth performance as apps built with a device-specific language.
In Flutter, all visible components of the app’s user interface, such as buttons, menus, and text fields, and their layouts, are implemented using pre-built reusable widgets. А widget-based architecture of Flutter apps allows developers to compose complex interfaces from simple components, customize their appearance and behavior, and maintain UI consistency across platforms.
Flutter has its own graphic rendering engine, Impeller, that provides a virtual canvas for drawing and combining widgets and sends the final interface to the device screen.
Flutter’s hot reload feature enables developers to check changes in code instantly without restarting the application, helping them rapidly debug and tweak the UI, prototype new features, and experiment with different designs.
Pros & cons
Pros
- Flutter allows developers to have precise control over every pixel in the interface and create unique, visually rich UI designs.
- Flutter apps provide fast performance and excellent responsiveness across devices due to native code compilation and the use of Flutter’s own rendering engine.
Cons
- Flutter can’t be used partially or for specific isolated features since it follows the “all-or-nothing” adoption strategy and requires rewriting the entire UI layer.
- It can be challenging for companies to find experienced Flutter developers.
- While Flutter is well-suited for quick prototyping, it’s not the best choice for future app evolution.
Companies using Flutter
Kotlin overview
Kotlin is a programming language created in 2010 and officially launched in 2016 by JetBrains, with Google actively supporting it since 2017. It was introduced to overcome several limitations of Java, such as code verbosity and null pointer errors that often cause app crashes, while staying fully interoperable with Java. Since 2019, Kotlin has been the preferred language for native Android app development with strong support from Google. It is also well-suited for creating web, desktop, and server-side applications. But apart from single-platform development, Kotlin offers dedicated technologies, Kotlin Multiplatform and Compose Multiplatform, that allow developers to build robust applications that seamlessly run across different operating systems and devices.
Key features
This cross-platform app development technology, available via a plugin as part of the Kotlin ecosystem, enables the sharing of a single Kotlin codebase to build Android, iOS, desktop, and web applications. With Kotlin Multiplatform, developers can reuse an application’s business logic, data models, and utility functions written in Kotlin across platforms and create platform-specific user interfaces for each target system using native components. Just like Flutter’s Dart, Kotlin code is compiled into native code specific for devices, delivering native experiences and consistent performance across platforms.
This UI framework within Kotlin Multiplatform is designed for creating user interfaces that can be shared across several platforms. On Android, Compose Multiplatform renders interfaces using Jetpack Compose (native), while on iOS it relies on a Skia-based canvas that mimics native UI behavior. As for desktop and web platforms, the framework extends the same UI code to Windows, macOS, Linux, and Web (via Wasm).
Kotlin-based Compose Multiplatform relies on the Skia graphics library, which provides a universal virtual canvas for drawing and combining composable UI elements like buttons, text, or layouts. This approach allows Skia to render the final interface consistently across different platforms.
Unlike Flutter, Compose Multiplatform allows for creating hybrid UI compositions when a developer can write most of the app in Kotlin and mix it with fully native modules within the same screen (e.g., to embed advanced native features like complex map views or augmented-reality (AR) interactions). This interoperability between the shared Kotlin UI and fully native platform UI is unique to the Kotlin ecosystem.
Pros & cons
Pros
- Kotlin allows for sharing business logic across different platforms.
- Kotlin allows the creation of concise, well-organized codebases that are easy to test and maintain.
- Compose Multiplatform gives developers flexibility in creating hybrid interfaces that share most of the UI written in Kotlin but embed native views written in platform-specific languages.
Cons
- Kotlin developers need to have a strong understanding of platform-specific UI technologies for building apps with a native UI layer.
- Unlike Flutter, which offers iOS-specific widgets, Compose Multiplatform currently doesn’t offer a built-in, comprehensive suite of iOS-styled components, which requires manual implementation of iOS designs from developers.
- Kotlin Multiplatform currently has limited hot reload capabilities, fully available for desktop platforms running on Java Virtual Machine (JVM) and partially for Android, which slows down UI iterations for iOS and web apps.
- Compose Multiplatform for web draws the interface as graphics on a virtual canvas instead of using standard web elements, which makes it difficult for search engines to read and index such pages. As a result, this framework is unsuitable for SEO-heavy static sites.
Companies using Kotlin Multiplatform
Need help with choosing a cross-platform technology?
Detailed comparison of Kotlin vs Flutter
Let’s compare various aspects of Flutter and Kotlin-based cross-platform framework, Kotlin Multiplatform and Compose Multiplatform, in detail to explore how these technologies support cross-platform development.
Flutter | Kotlin | |
|---|---|---|
Platform compatibility | Both Flutter and Kotlin support mobile (Android, iOS), web, and desktop (Windows, MacOS, Linux) platforms by default. | |
UI development | Flutter offers an extensive collection of pre-built customizable widgets from multiple design categories, including Styling, Layout, Text, and Animations. Developers can combine and customize these reusable components to quickly build complex, unique interfaces without writing code from scratch for common UI elements. Flutter also provides widgets that align with Cupertino and Material Design guidelines to help developers preserve iOS- and Android-specific aesthetics in their applications. | When building cross-platform mobile apps using Kotlin, developers can use native UI frameworks (Jetpack Compose for Android and SwiftUI for iOS) to deliver authentic user experiences and fully utilize device-specific capabilities. This ensures the apps look, feel, and perform like fully native apps on each mobile platform. Kotlin also provides Compose Multiplatform for sharing user interfaces across several platforms. Currently, the framework is fully stable for mobile and desktop, with web support in active development. Using Compose Multiplatform, developers can achieve consistent visual design and behavior in apps across different platforms while reusing the code instead of writing it for each target system. |
App performance | In Flutter apps, Dart code is compiled into the native code of each target operating system, enabling high-performance execution and direct access to platform-specific features and APIs. However, Flutter doesn’t use native UI elements and draws them with its own high-performance engine, so that even highly interactive interfaces with complex animations remain smooth and responsive. All this makes Flutter apps highly consistent across mobile, desktop, and web platforms while still delivering native performance. | When used in cross-platform development with Kotlin Multiplatform, the shared code written in Kotlin is compiled into the format specific for each native platform (i.e., JVM bytecode for Android and desktop, JavaScript (or WebAssembly) for web, and native binaries (via LLVM) for iOS). This allows the shared backend logic to run efficiently as a native artifact on all of them, without requiring a bridge for execution. |
Developer tools | Both technologies offer robust sets of development tools that streamline the development cycles and improve developer experience. Flutter and Kotlin support multiple integrated development environments (IDEs), including the industry-leading Android Studio and IntelliJ IDEA that provide advanced static analysis, refactoring, and native debugging capabilities. Such flexibility gives developers freedom to use their preferred environment and adapt their workflows to the project needs. | |
| Beyond that, Flutter offers performance and debugging tools called DevTools that help developers inspect the widget tree, analyze memory, and debug layout issues in real-time, shortening iteration cycles. | Kotlin Multiplatform automates many of the development tasks, helping developers be more productive and deliver high-quality apps faster. Unlike Flutter, which has its own tooling, Kotlin Multiplatform integrates directly with standard platform profiling tools (like Xcode Instruments for iOS and Android Profiler for Android), so developers can analyze and debug app performance issues using the native tools they already trust. | |
Learning curve | Since Flutter uses its own language, Dart, developers must learn a new syntax. However, Dart is designed to be simple and familiar to anyone knowing JavaScript or Java. The main challenge lies in mastering the declarative UI paradigm and the widget-based model, but detailed, beginner-friendly documentation and a unified ecosystem make the onboarding process smooth. | As for Kotlin Multiplatform, the transition is seamless for Android developers as they already know the language. However, the learning curve is steep for teams new to the ecosystem due to the complexity of the Gradle build system and the need to understand multiplatform architecture. Unlike standard Android development, Kotlin Multiplatform requires knowledge of platform-specific constraints (especially those for web) and a shift away from Java-dependent libraries. |
Key similarities & differences of Flutter and Kotlin
Similarities
Despite the differences in underlying technologies and development approaches of Flutter and Kotlin-based frameworks, they share some traits that make them both strong choices for cross-platform development.
- Enable developers to create a single codebase for apps that run on iOS, Android, web, and desktop (Windows, macOS, Linux) platforms
- Enable the creation of cross-platform apps with native performance and great maintainability
- Streamline the app development process
- Both supported by Google
- Have extensive ecosystems of developer tools as well as pre-built packages, libraries, and UI components
- Power apps with millions of users
- Have a moderate learning curve
Flutter | Kotlin (KMP, CMP) | |
|---|---|---|
Nature | UI framework/Software development kit (SDK) with a rendering engine | Software development kit (SDK)/Technologies for sharing app logic and UI using the Kotlin language |
Creator | | JetBrains |
Released in | 2017 | 2016 |
Language support | Dart | Kotlin |
Code sharing | Both business logic and UI are shared across platforms | Shared business logic, database, and networking (KMP); UI sharing (CMP) |
User interface | Widget-based | Can be platform-specific or shared |
UI components | Offers its own set of UI components | KMP uses native UI components for iOS, Android, web, and desktop; CMP enables shared UIs |
Ecosystem | Mature ecosystem with an increasing number of code packages | An expanding ecosystem of dedicated libraries |
Community | Active, rapidly growing community | Large, established community |
Popularity trends for Flutter & Kotlin
Flutter statistics
| In 2025, Flutter ranked as the fifth open-source project with the highest number of first-time contributors on GitHub, up from sixth place in 2024, which indicates the rapid growth of its developer base and strong community support. | |
|---|---|
| Flutter is the second most popular technology for developing mobile apps, accounting for 26% of apps in Google Store and 16% of apps in Apple’s App Store. | |
| As of January 2026, Flutter’s Dart ranks 15th place according to the number of people looking for tutorials on each language. | |
| In 2025, 6.4% of companies reported demand for Flutter developers, placing it 12th among other most popular frameworks. |
Kotlin statistics
| Kotlin is used by over 2.5 million developers worldwide, which indicates sustained adoption of the language. | |
|---|---|
| 79% of apps on Google Play are written using Kotlin. | |
| 50% of professional Android developers use Kotlin as the main programming language. | |
| Kotlin was among the top 15 most popular technologies used by professional developers in 2025. | |
| As of January 2026, Kotlin ranks 17th in popularity based on the number of language tutorial searches. | |
| Kotlin was demanded by 6.9% of companies in 2025, which makes it the 13th most sought programming language and indicates popularity comparable to Flutter. |
Entrust your cross-platform project to Itransition
Typical use cases for Flutter & Kotlin
When to use Flutter | When to use Kotlin |
|---|---|
| Flutter is the best choice for building brand-first cross-platform applications from scratch when you are looking to ensure a pixel-perfect, consistent visual identity across both iOS and Android. Flutter is specifically recommended for creating:
Companies that plan to develop a cross-platform mobile application with simpler UI requirements can also consider choosing React Native over Flutter. | Kotlin, when used through Kotlin Multiplatform and Compose Multiplatform, is a versatile technology suitable for both new cross-platform app development initiatives and established products. It is the best option for creating:
|
95%
employee satisfaction rate
Corporate cross-platform mobile app
Itransition developed a Flutter application for iOS and Android to help a global software development company centralize information on corporate discounts and events and facilitate its provision to the staff. Soon after the release, 80% of employees downloaded the app to monitor corporate discounts and register for corporate events.
3,000+
registered users
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30+
new healthcare institutions attracted
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85%
of orders made via kiosks
Self-service kiosk app for restaurants
A 24/7 restaurant chain partnered with Itransition to build a Kotlin application for Android self-service kiosks. The app was successfully launched on over 3,000 kiosk devices in more than 500 restaurants, helping speed up order processing by 30%.
How Itransition can help
With a proven track record of delivering Flutter and Kotlin solutions of various scales and complexity, Itransition can guide you in choosing the most appropriate technology for your project and develop high-performing applications in line with your requirements.
Kotlin app development
We develop user-friendly applications with robust capabilities that run across mobile, web, and desktop platforms and deliver a native-like look and feel across them all.
Flutter app development
We build cross-platform applications with sophisticated user interfaces and intricate designs, ensuring their consistent performance across devices.
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