Is Now the Time to Convert Existing App to Flutter? A Guide for Business Leaders

This blog explains why enterprises should convert existing app to flutter to cut costs, speed up releases, and deliver consistent user experiences. It covers migration scenarios, solutions to common concerns, a real case study, and how Kody Technolab helps CEOs and CTOs plan safe, scalable migrations.

Many companies are choosing to convert existing app to flutter as costs and delays from managing separate platforms keep growing. CEOs and CTOs often deal with two development teams, double the expenses, and slower release cycles that reduce competitiveness. Every new feature feels like an uphill battle when iOS and Android demand separate efforts.

Flutter offers a more practical path. Businesses can modernize in phases, keep the current app live, and measure results with less risk.

In 2023, Statista reported that 46% of developers worldwide actively used Flutter, making it the most adopted cross-platform framework. That level of trust reflects its stability and performance across industries.

For leaders in the USA, UK, UAE, and other high-end markets, Flutter, for your enterprise app, provides a way to scale faster, control budgets, and build user-focused products. Companies can even add flutter to existing app features without committing to a full rebuild.

Why should you convert existing app to Flutter in 2025?

The decision to convert existing app to flutter often begins with your own frustrations. Maintaining two platforms drains your resources. You end up paying for separate teams, waiting longer for releases, and struggling to keep quality consistent across iOS and Android.

Flutter changes this reality for you. With a single codebase, your team can deliver features for both platforms. You cut payroll costs, speed up delivery, and keep your roadmap predictable. Instead of fighting delays, you can focus on growth and customer experience.

What you gain by migrating your existing apps to Flutter

• You release updates faster because all work happens in one environment.
• You stretch budgets further since duplicate development disappears.
• Your users enjoy the same performance and design across every device.
• You can migrate in phases, which avoids downtime and disruption.

Native vs Flutter: Maintenance comparison

Factor	Native (iOS + Android)	Flutter (Single Codebase)
Developer Teams	Two separate teams	One unified team
Maintenance Costs	Nearly double	Up to 30% lower
Update Timeline	2–3 months	3–4 weeks

Executives who want scale, speed, and efficiency see Flutter as more than a framework. It is a way to convert an android app to flutter or convert ios app to flutter without risking stability while preparing the business for long-term growth.

What does converting your existing Android or iOS app to Flutter mean?

To convert existing app to flutter means moving from two separate codebases to one unified system. Instead of paying for Android and iOS teams separately, you can rely on a single team to deliver both platforms. This reduces your costs and speeds up delivery.

Flutter is Google’s open-source framework for building mobile applications. With it, you release features faster, keep your budgets predictable, and give your customers a consistent experience across devices.

Since 2019, Flutter has included the add-to-app functionality, making adoption even more practical. With add-to-app, you can add flutter to existing app modules without replacing the full system. You preserve your current workflows while gaining smoother interfaces and better stability. If you already run on Android or iOS, you can convert android app to flutter or convert ios app to flutter step by step, keeping your operations safe from disruption.

At Kody Technolab, we’ve applied this approach for clients like a milk delivery company that wanted faster updates and a flexible design without losing reliability. We mapped the migration path, integrated Flutter modules with top Flutter widgets, and delivered a cross-platform app. The result was quicker updates, lower maintenance costs, and customers who enjoyed a seamless experience across every device.

When should you convert an existing app to Flutter? Key scenarios for B2B success

The best time to convert existing app to flutter is when your current technology starts slowing down growth. You probably notice the signs early. Updates take longer, costs rise every year, and user complaints pile up across platforms.

You usually recognize the need to convert app to flutter in clear scenarios:

• You want to expand into new markets, but the cost of running two teams holds you back.
• Your customers expect faster features, but updates crawl through separate iOS and Android pipelines.
• Your brand image suffers because design looks different on each device.
• Your maintenance budgets grow, but your returns stay flat.

Flutter helps you handle these challenges with one codebase. You can add flutter to existing app modules without scrapping your current investments. The result for you is lower costs, faster releases, and a consistent experience across platforms. These benefits strengthen your long-term growth.

1. When should you convert your Android or iOS app to Flutter during a major update?

You’ve had your Android or iOS app in the market for years. The app still works, but every update takes longer, costs more, and frustrates your team. At some point, maintaining two codebases stops being sustainable. At that stage, many leaders look at how Flutter works and choose to convert existing app to flutter. 

Here are the real moments when it makes sense:

• You plan to roll out major features but release cycles drag because iOS and Android move at different speeds.
• A redesign is overdue, and keeping the look and feel consistent across platforms drains both money and time.
• Expansion plans are stalled because two development teams push your budget beyond what makes sense. 
• Customers complain about inconsistent experiences, hurting your brand reputation.
• Annual maintenance costs rise, but the return does not. 

Flutter solves these challenges with one shared codebase. Companies can add flutter to existing app modules without scrapping what already works. If your team runs on Swift, you can convert swift to flutter gradually. The payoff is faster delivery, lower maintenance, and a user experience that finally feels the same everywhere. 

2. Why technical challenges are the right time to convert existing app to Flutter

Every app eventually runs into problems that patchwork fixes cannot solve. Security gaps appear, performance slows, or the design feels outdated. When you face these issues, migrating is often smarter. You convert existing app to flutter instead of fixing problems twice across platforms. 

Here are common signs you should take action:

• Your app has security vulnerabilities that demand significant redevelopment. 
• Language and localization support fails, creating poor user experiences in new markets. 
• Animations and graphics render slowly, frustrating customers. 
• UI and UX behave differently across devices, damaging brand trust. 
• You need to develop a PWA or web version, but building it separately is costly.

Flutter addresses these problems with a single codebase. Instead of managing two development pipelines, you can convert app to flutter and handle updates in one environment. For businesses not ready for a full rebuild, Flutter allows you to add flutter to existing app modules step by step. 

If you run a Swift project, you can convert swift to flutter gradually. A phased approach keeps operations stable while unlocking faster updates, lower maintenance costs, and a consistent user experience across every platform. 

3. How you can add Flutter to existing app and launch full features faster

• Even if you don’t need to replace or upgrade your two existing native language apps but simply want to add a new feature, Flutter can still be the right approach. 
• Many businesses now choose to add Flutter to existing apps because it enables faster development without disturbing the original native code. 
• This makes it easy to introduce new features using Flutter while maintaining the integrity of your existing architecture.
• Now, here’s something from our own experience. We had developed and successfully deployed a native Android app for a subscription-based milk delivery service provider. Later, the client approached us to build an iOS version of the same app.
• That was the right moment to suggest a smarter alternative: convert the existing app to Flutter. This move allowed them to go cross-platform, which brought multiple benefits. 

The biggest advantage was a significant reduction in maintenance cost and effort, thanks to having just one codebase. And there were more compelling reasons why Flutter became the preferred choice over rewriting the app in Swift.

What are the top reasons to convert app to Flutter in 2025?

When your business needs to modernize or scale, it often makes sense to convert existing app to flutter. Flutter combines efficiency and flexibility, helping you reduce costs, deliver features faster, and keep your customers satisfied across platforms.

Here are the main reasons enterprises move forward with Flutter:

• You handle complex projects more easily because Flutter includes powerful tools and libraries.
• Your app achieves performance levels comparable to native development, ensuring a smooth user experience.
• You manage only one codebase, which supports both Android and iOS.
• You shorten testing cycles, since one codebase covers all platforms.
• You work with a modern framework designed with built-in enterprise features.
• You accelerate releases with Hot Reload, which shows changes instantly during development.

If you already run a native iOS app, Flutter offers a cost-effective way to expand. You can convert ios app to flutter and reach Android users without rebuilding from scratch. The same applies if you run Android only; you can convert android app to flutter and go cross-platform faster. 

For companies with established apps, it is also possible to add flutter to existing app modules. This approach keeps your system live while gradually upgrading features.

Moving to Flutter gives you lower maintenance costs, faster go-to-market timelines, and a scalable foundation for future growth.

Key Considerations Before Converting to Flutter for a Smoother Migration

Before you convert an existing app to flutter, you need to prepare carefully. A migration without planning can create delays, higher costs, and user issues. Evaluating your app, dependencies, and team upfront ensures smoother execution and predictable business outcomes.

Assess your current app’s complexity

Start by reviewing the structure of your existing app. Look at the number of features, third-party integrations, and the backend design. A simple app with few dependencies is easier to migrate than a complex system with custom animations or large databases. Understanding this upfront helps you estimate effort, cost, and required expertise.

Understand Flutter’s Capabilities and Limitations

While Flutter is powerful, it’s essential to understand what it can and cannot do. Flutter excels at creating visually appealing, high-performance apps with a single codebase. 

However, suppose your app relies heavily on platform-specific features or third-party libraries that don’t have Flutter support. In that case, you might need to find workarounds or consider how to integrate native code with your Flutter app.

Evaluate the Need for Custom Widgets

Flutter allows for the creation of custom widgets, which can be a double-edged sword. On the one hand, it offers the flexibility to design a unique UI/UX; on the other, it might require additional effort to replicate specific UI elements from your existing app. 

Assess whether your app’s design can be easily adapted to Flutter’s material or Cupertino widgets or if you’ll need to invest time in custom widget development.

Plan for Integration Testing

Migrating to Flutter means you’ll have a single codebase for both iOS and Android, but it doesn’t eliminate the need for thorough testing on both platforms. Plan for integration testing to ensure your Flutter app performs well and provides a consistent user experience across devices. 

The integration testing must include testing third-party integrations, push notifications, and platform-specific features.

Review Third-party Dependencies

List all external libraries, SDKs, and APIs your current app uses. Check if equivalent packages exist in the Flutter ecosystem. If not, plan alternatives or consider native integration through platform channels. This preparation avoids costly surprises during migration.

Understand the Migration Impact on Your User Base

Consider how the migration will affect your existing user base. A well-executed migration to Flutter should be seamless for your users, offering them a better and more consistent experience across platforms. 

However, it’s better to plan for any potential downtime, data migration issues, or changes in app behavior that could affect user satisfaction.

Hire experienced Flutter developers

Migrating your existing Android, iOS, or both apps to Flutter requires a team of experts who know Flutter inside out as well as native technologies. The development team must have command over the framework’s underlying programming language, Dart, its UI library, and other features. 

Here’s the guide for Flutter developer skills you must look out for to build a strong team. 

Now, moving ahead with the topic,

How do you convert existing app to Flutter successfully?

To convert existing app to flutter, you start by deciding how Flutter will fit into your system. For many companies, the best path is to integrate Flutter as a library or module that handles specific parts of the application.

If you are a CEO or CTO without deep technical knowledge, your first step is hiring skilled Flutter developers. You can follow our detailed guide on how to hire Flutter developers to avoid common mistakes and build the right team. With the right people, your migration delivers measurable business value.

The Flutter module reflects the application’s user interface. You can create this module with the “flutter create -t module” command. This process builds a project with a structure designed to work alongside your existing code.

The further course of action that we followed is the same as described in the official Flutter documentation.

Add Flutter to an existing Android app:

Things that Flutter allows us to do when integrated into Android apps.

• You can add a Flutter SDK hook to your Gradle script to auto-build and import the Flutter module.
• If you want to integrate the Flutter module into your own build system, build your Flutter module into a generic Android Archive (AAR) that also better Jetifier interoperability with AndroidX.
• Use FlutterEngine API for starting and continuing your Flutter environment independently.
• Module import/creation wizard allows you to co-edit Android and Flutter projects in Android Studio.
• It supports apps built with Java and Kotlin.
• Flutter plugins can be integrated into the preexisting platform and used for Flutter modules to interact with the platform. 
• Using the Flutter attach function from an IDE or the command line, you can connect to an app that contains Flutter and debug it or reload it using a stateful hot reload.

What can you learn from a real case study of converting an existing app to Flutter?

One of our clients approached us with a clear problem. They had built a native Android app for MilkMore, a subscription-based milk delivery service. The app worked but performance issues and high maintenance costs were slowing growth. They needed a better way forward, so they decided to convert existing app to flutter.

Background:

MilkMore is a subscription-based milk delivery app, that allows users to create custom subscriptions for fresh milk and other dairy products delivery. The Android version worked well initially, but scaling across platforms created problems. Building an iOS app separately would double costs and increase maintenance. The leadership team wanted consistency, lower effort, and faster releases. 

Solution:

Our team reviewed the Android codebase and design in detail. We used Flutter widgets to create a new interface that matched the original look but improved speed and stability. We integrated payment gateways and other APIs to ensure smooth transactions.

The phased strategy let the business add flutter to existing app features without rebuilding from scratch. The new structure also meant they could later convert ios app to flutter with minimal work. This gave them one codebase ready to support both platforms.

Results:

After the migration to Flutter, the MilkMore app saw significant improvements in performance and user experience. The new Flutter-based UI design was well-received by users, resulting in increased engagement and higher user ratings.

Additionally, our development team was able to reduce development time and costs by using Flutter’s built-in tools and widgets, which made the development process more efficient.

Lessons learned:

From this unique project, we learned that migrating an existing app to Flutter requires a deep understanding of the existing codebase and design, as well as careful planning and testing. Working closely with the client and using Flutter’s built-in tools and widgets help streamline the development process and reduce costs. 

If you want to know the best Flutter widgets and Flutter tools, explore these lists that we have compiled after thorough research.

Now let us have a glimpse of the app’s look that we converted into Flutter.

Native Android Application:

Flutter Application:

What concerns do companies raise when they convert existing app to Flutter?

When you decide to convert existing app to flutter, questions about cost, timeline, performance, and risk always come up. Addressing these concerns early helps you plan with confidence and ensures your migration improves growth instead of slowing it.

1) Will migrating my existing app to Flutter be expensive and time-consuming?

The cost and timeline depend on the complexity of your current app. If your app has a simple UI, migration is faster. Large apps with custom animations or heavy integrations require more effort. A phased approach helps control cost and avoids downtime. 

Many companies add flutter to existing app features first, measure the results, and then expand. Over time, businesses save money because one codebase replaces two.

2) Will my app look and perform the same after converting it to Flutter?

Yes. With custom widgets, Flutter can replicate your current design and maintain brand consistency. In many cases, design and performance improve because one framework manages both iOS and Android. 

Executives often convert ios app to flutter when they want a consistent experience across platforms without rebuilding from scratch. Performance is comparable to native apps, provided your development team tests thoroughly.

3) Will my existing code and third-party integrations work in Flutter?

Most likely. Flutter supports integration with Java, Kotlin, and Swift, so your current logic remains useful. Many popular SDKs and APIs already have Flutter packages. Where gaps exist, native bridges connect your old code with Flutter modules. 

Companies often convert android app to flutter while keeping critical native modules for payments, authentication, or analytics. An experienced Flutter team ensures smooth integration and reliable results.

4) Will my app remain reliable after future platform updates?

Yes. Flutter is updated regularly and designed to keep apps compatible with new iOS and Android releases. Stable release channels and dependency audits help your team manage upgrades predictably. 

Developers use hot reload to shorten testing cycles during updates, which means your app adapts quickly to changes. With planning, your app stays reliable and scalable long after you convert app to flutter.

5) Will my existing users be affected during migration?

Not if the migration is managed properly. The safest approach is a staged rollout. Keep your current app live, move one feature to Flutter, and track performance. As confidence builds, you expand further. 

When you convert existing app to flutter this way, customers only notice faster updates and smoother experiences. Done correctly, migration improves user satisfaction and protects your brand reputation.

So, all you need is to hire experienced flutter developers to ensure that the migration process is done efficiently and with minimal impact on users.

What is the expected time and cost to convert an existing app into Flutter? 

The time and cost to convert an existing app into Flutter can vary depending on the app’s complexity and the project’s requirements. For a simple example, let’s say you have a basic eCommerce app with five screens that you want to convert to Flutter.

Time and Cost to Convert Existing App to Flutter

App Type	Development Time	Estimated Cost	Notes
Basic App (e.g., 5 screens)	10–15 working days	~$10,000 – $20,000	Best suited for businesses that want to quickly convert app to Flutter with minimal logic and UI complexity.
Moderate App (e.g., 10–20 screens)	1 to 2 months	~$20,000 – $30,000	Ideal for companies looking to add Flutter to existing apps with moderately complex UI/UX and some third-party integrations.
Complex Enterprise App	3 to 6 months	~$35,000 – $100,000+	For full-scale transformations where businesses convert existing app to Flutter across multiple modules, platforms, and deep features.

Key Factors That Affect the Cost to Convert an Existing App to Flutter

Several core elements influence the total cost when you decide to convert an existing app to Flutter. Understanding these variables helps in planning a realistic budget and timeline.

1. App Complexity

A basic app with limited functionality will require less effort than one with advanced logic, data handling, or animations. The more complex your current app, the higher the development cost to convert the app to Flutter.

2. UI/UX Design Requirements 

If your existing app has a unique or intricate design, recreating that using Flutter’s widget system can require additional effort. Custom components often take more time compared to using standard Flutter widgets.

3. Third-party Integrations

Integrations like payment gateways, CRMs, or real-time databases may need reconfiguration or native bridges when you add Flutter to existing apps. The more integrations, the more time and resources required.

4. Platform Expansion Goals

Planning to use this migration to launch your app on both Android and iOS? Your team will also need to evaluate how to convert an iOS app to Android or vice versa, which may add complexity depending on platform-specific features.

5. Code Quality and Architecture of the Existing App

Clean, modular codebases are easier to integrate or rewrite. If your current app is poorly documented or tightly coupled, restructuring may increase the overall effort required to add Flutter to existing Android apps.

6. Team Experience

The more experienced your Flutter developers are, the quicker they’ll be able to identify reusable components and streamline the migration. This directly impacts cost-efficiency and delivery speed.

So, based on these factors:

• A small app may take up to 15 days and cost around $10K,
• If the app has many screens and moderately complex UI/UX, it may take up to 1 to 2 months and cost about $20-$30k,
• And the app, with numerous screens and sophisticated app design, requires around 6 months to be converted entirely into Flutter and may cost $30k to $100k. 

However, this is only an estimate, and the actual time and cost can differ depending on your specific project requirements. And let’s not forget about the cost of hiring Flutter developers. 

Understanding these cost drivers will help you plan smarter and avoid surprises during development. Whether you’re looking to convert existing apps to Flutter or add Flutter to existing apps, aligning your goals with these factors ensures a smooth and cost-effective migration.

Hence, it’s best to consult with an experienced Flutter development company to get an accurate estimate for your specific project.

Kody Technolab Ltd’s role in converting existing apps to Flutter

At Kody Technolab Ltd, we specialize in helping businesses modernize their digital products. Many CEOs and CTOs come to us when separate Android and iOS teams slow delivery, raise costs, and create inconsistent experiences. For them, the best decision is to convert existing app to flutter and manage everything with one shared codebase.

Our Flutter developers have handled projects where clients needed to add flutter to existing app modules, migrate gradually, or fully convert ios app to flutter or convert android app to flutter. Every approach is planned around your business goals, budget, and timelines.

As one of Flutter’s early adopters, we know the framework inside out. With years of expertise in flutter app development, our team ensures lower maintenance costs, predictable delivery, and consistent user experiences across devices.

Book a free consultation today to see how our team can accelerate your Flutter migration.