Write your code once and deploy it everywhere. Sounds great, right? Well, here's the thing about cross-platform mobile development: everyone wants it to be easier.
Enter Flutter and Kotlin Multiplatform, two contenders in the "write once, run anywhere" arena.
Flutter, backed by Google, is the flashy newcomer with its own language (Dart) and a "everything is a widget" philosophy. Kotlin Multiplatform, on the other hand, is like that friend who always brought great snacks to movie night and has now decided to host the whole party – familiar and reliable, but suddenly aiming to do a lot more.
Is it worth it to learn Dart for Flutter, or should you stick with Kotlin?
Let's break down these two contenders and see if one is actually better than the other.
Flutter vs Kotlin Multiplatform: Head to Head Comparison
The table below highlights the quick differences between Flutter vs Kotlin Multiplatform.
What is Flutter?
Flutter is a reactive cross-platform mobile development framework created by Google and uses Google’s Dart language. Flutter was initially unveiled at the 2015 Dart developer summit. Three years later, Google released the first stable release version — Flutter 1.0 — on December 5, 2018, at the Flutter Live event. It is used to develop applications for Android, iOS, Windows, Mac, Linux, Google Fuchsia, and the web using a single code base. Google’s strong support helped Flutter quickly overtake other cross-platform options like React Native. At its core Flutter is a reactive framework that comes with a large number of ready-to-use widgets. Flutter applications are compiled to native code and use a high-performance rendering engine, delivering smooth animations and near-native performance across platforms.
Flutter pros
Some of the advantages of cross-platform mobile app development using Flutter include:
- Hot Reload: One of the biggest pros of using Flutter is the ability to get a near-instant reflection of changes. Hot Reload allows developers to make changes to the codebase and not have to restart the application to see the change reflected.
- Cross-platform development from one codebase: With Flutter, writing one codebase can support iOS and Android platforms. The same codebase can also be used for the other platforms supported by Flutter including the web. And with Flutter having its widgets and designs you have the option to create the exact same app on both platforms. Or have them vary if you wish.
- Cut down on debugging time: Having the same exact app for both platforms and the same codebase means that you will only need to debug once instead of separately for each platform.
- Fast fluid UI: Flutter delivers smooth and consistent UI performance through its custom rendering engine, allowing interfaces to feel responsive and visually consistent across devices and platforms.
- Great app design: Flutter has its own custom widgets and doesn’t use native system components. Flutter also has a very user-friendly UI. This distinct yet very attractive look gives Flutter a big advantage over React Native.
- Same app UI, even on older devices: The non-reliance on native components and having cross platforms be the exact same also works for older vs newer devices. Apps will look the same whether on older iOS/Android devices or newer versions.
- Strong for rapid iteration and experimentation: Flutter excels when teams need to move quickly, validate ideas, and iterate on product design without maintaining multiple platform codebases. Many teams also scale Flutter apps well beyond early prototypes into long-term production systems.
- Flutter community and support: Traditionally due to Flutter being a newer option than React Native, community support has always been a disadvantage when compared. But due to its surging popularity Flutter has surpassed React Native in popularity and community support. Flutter currently has 158,000+ stars on Github while React Native has 113,00+ stars. Google has also continued to strongly support Flutter and its development and now it is a very stable and mature option.
- Open source and completely free: Flutter is completely free to use, as opposed to other options like using an app builder or no-code solutions for your cross-development needs.
Flutter cons
While Flutter is surging in popularity amongst the cross-platform development tools out there at the moment, it is certainly not perfect. Some of the disadvantages of Flutter include:
- Dart language: While the Dart language itself is a very strong programming language, it was only developed alongside Flutter. In order to develop apps on Flutter, you will need to specifically learn how to use and write Dart. This barrier for entry can be discouraging to many users who prefer to easily adapt to a common language such as Javascript as is the case with React Native.
- Platform-specific capabilities: While Flutter’s ecosystem covers most common use cases, certain platform-specific features may still require custom native integrations, particularly for deeply embedded system functionality.
- App sizes: Although Flutter has been working on this and they have their own guide to reducing file sizes, Flutter apps tend to be a larger size than native ones.
Check out our essential list of Flutter resources and development tools.
What is Kotlin Multiplatform?
At first glance, comparing Kotlin and Flutter might raise some eyebrows due to Kotlin being traditionally known as a programming language. However, JetBrains released Kotlin Multiplatform in 2020 as an additional feature of the language that helps it expand beyond Android app development. Kotlin Multiplatform allows developers to share business logic across platforms while retaining full control over native UI and platform-specific capabilities.
Kotlin Multiplatform pros
- Modular integration: Probably the biggest benefit in favor of Kotlin is that it’s an SDK and not a framework. This means that teams with existing apps can simply add a module or migrate a small part to assess its viability without a huge commitment. This really helps Kotlin address the biggest deterrent when moving to a new codebase.
- Easy to learn: Kotlin as a programming language is very popular already and its syntax is very similar to other popular languages such as Swift and Java. This also helps reduce the barrier for entry and encourages developers to pick up Kotlin as an alternative.
- Shared business logic with native flexibility: Kotlin Multiplatform enables teams to share core logic such as networking, data access, and domain models, while still building fully native user interfaces and integrating deeply with platform APIs.
- Native UI experience: Kotlin Multiplatform unlike Flutter does not demand developers to follow its own UI. It lets you utilize native UI elements to its fullest as if you are developing natively.
- Native performance: This utilization of native components helps Kotlin developed apps perform as efficiently as they would as natively developed apps. This is a much sought-after advantage for various developers looking to make something beyond an MVP.
Kotlin Multiplatform cons
- Selective maturity across features: Kotlin Multiplatform is production ready for core use cases such as shared business logic and data layers. Some advanced features and UI sharing approaches continue to evolve, requiring teams to evaluate stability based on their specific needs.
- Community support and libraries: Being a relatively new alternative, libraries and community support is somewhat limited. However, it's worth mentioning that they have been rapidly growing over the past few years and show no sign of slowing.
- Not a closed solution: Kotlin Multiplatform still needs mobile teams to be at least familiar with the different tech stacks. Utilizing a lot of native components means that it won't be sufficient to be familiar with only Kotlin on its own. This isn’t the case with Flutter where you can do everything purely using Flutter.
- Higher coordination overhead: Kotlin Multiplatform typically requires closer collaboration between platform teams and familiarity with native ecosystems. This can increase upfront development effort compared to a single-framework approach, but often pays off in long-term maintainability and performance.
How to Choose Between Flutter and Kotlin Multiplatform
Flutter and Kotlin Multiplatform approach cross‑platform development from different angles, and neither is a universal winner. The right choice depends on how your team builds, ships, and maintains mobile apps at scale.
Flutter is a strong fit for teams that prioritize fast iteration, UI consistency, and a single development workflow across platforms. Kotlin Multiplatform works well for teams that value native UI, performance, and gradual adoption alongside existing iOS and Android codebases.
Regardless of which path you choose, the real challenge comes after launch. As apps grow, production stability, performance regressions, and hard‑to‑reproduce edge cases become inevitable. That’s where having deep visibility into real user behavior matters more than the framework itself.
Luciq helps teams using both Flutter and Kotlin Multiplatform move from reactive debugging to proactive resolution by automatically surfacing issues, correlating errors with user impact, and accelerating fixes across platforms. No matter which technology wins your evaluation, pairing it with agentic mobile observability ensures your app delivers a reliable, high‑quality experience at every release.
Frequently Asked Questions
Is Kotlin good for cross-platform development?
Yes, Kotlin Multiplatform is well suited for cross-platform development when the goal is to share business logic across platforms while keeping fully native user interfaces. It’s especially effective for teams with existing Android and iOS apps, as it allows modular adoption without requiring a full rewrite.
Is Kotlin Multiplatform faster than Flutter?
Kotlin Multiplatform can offer stronger native performance in scenarios that rely heavily on platform-specific APIs and native UI components. Flutter also delivers excellent performance for most applications, particularly when using its custom rendering engine. In practice, the decision often comes down to architectural needs and iteration speed rather than raw performance alone.
When to use Kotlin Multiplatform?
Kotlin Multiplatform is a good choice when you want to share core business logic while preserving native UI, need deep integration with platform APIs, or want to incrementally adopt cross-platform development within existing apps. It works particularly well for teams already familiar with Kotlin, Java, or Swift.
Is Kotlin Multiplatform replacing Flutter?
No, Kotlin Multiplatform is not replacing Flutter. Both serve different development approaches. Flutter focuses on maximizing code sharing and UI consistency across platforms, while Kotlin Multiplatform prioritizes native UI and shared business logic. Many teams evaluate both based on their product and team structure rather than treating them as direct replacements.
Does Google use Kotlin or Flutter?
Google uses both Kotlin and Flutter. Kotlin is officially supported and widely used for native Android development, while Flutter is a cross-platform framework created and maintained by Google for building applications across mobile, web, and desktop platforms.
What is the difference between Flutter and Kotlin Multiplatform?
Flutter is a framework that provides its own UI system and requires developers to use Dart, enabling extensive code sharing across platforms. Kotlin Multiplatform is an SDK that focuses on sharing business logic while allowing teams to build native user interfaces. Flutter emphasizes development speed and UI consistency, while Kotlin Multiplatform emphasizes native control and architectural flexibility.
Does framework choice affect mobile observability and app stability?
Yes. While Flutter and Kotlin Multiplatform take different architectural approaches, both introduce additional layers between your code and the end user, which can make issues harder to detect once an app is in production. Performance regressions, crashes, and edge cases often appear differently across platforms, devices, and OS versions regardless of the framework used.
This is why mobile observability matters. Using an agentic mobile observability platform like Luciq helps teams gain real‑time visibility into errors, performance issues, and user impact across both Flutter and Kotlin Multiplatform apps. By automatically surfacing issues and accelerating resolution, observability ensures that framework choice doesn’t become a blind spot after launch.