How Long Does Android to HarmonyOS Migration Take?

Planning for a seamless HarmonyOS migration? Most teams that plan for this approach often ask two questions. One is: how long it will take for the migration and how much it will cost.

Before diving into the details, you should know what HarmonyOS is. It is Huawei’s proprietary operating system with its own kernel, runtime, language (ArkTS), and service ecosystem. It is a completely independent platform, not an Android variant.

On timelines: a simple app takes roughly 3 to 4 months, while a complex fintech or enterprise app requires at least 6 to 12 months.

However, the final answers depend heavily on your Android app’s complexity, the depth of Google service dependencies, and whether your team has prior HarmonyOS experience. This HarmonyOS app development and the complete migration details guide give you honest, detailed answers to all of it.

The Unvarnished Truth: It’s Not a Port, It’s a Rewrite

Most planning documents skip this part entirely, and that is exactly why timelines break.

The direct answer: HarmonyOS NEXT is not Android. You cannot port your app. You can rebuild it.

When teams research how to migrate an Android app to HarmonyOS, they assume the process works like switching frameworks or updating an SDK. That assumption is wrong, and it is the single most common reason migration projects run over budget and over schedule.

Now, coming to the part, why is HarmonyOS NEXT architecturally incompatible with Android? 

HarmonyOS versions 1 through 4 ran on an Android compatibility layer. That layer no longer exists. In October 2024, HarmonyOS NEXT launched commercially and continues through HarmonyOS 5 and HarmonyOS 6. These are a clean-slate operating system and do not support APKs. It does not run HarmonyOS Android apps natively under the old compatibility line.

What this means practically for your migration:

• HarmonyOS Android apps cannot run directly on HarmonyOS NEXT devices
• Every screen, component, and navigation flow must be fully rebuilt in ArkUI and ArkTS
• Every Google Mobile Services dependency must be replaced with a Huawei Mobile Services equivalent

How to Understand the Real Things? 

The WeChat example makes these points more solid. WeChat has almost 1.34 billion users and is one of the largest mobile engineering teams in the world. Migrating WeChat to HarmonyOS NEXT requires rewriting the functional code so it can be easily rewritten from scratch. 

Even so:

• The migration required a full functional rewrite from scratch
• It took several months and a significant capital investment
• As of August 2025, the HarmonyOS version is still missing nearly 30 features compared to its Android counterpart, including real-time location sharing and image text recognition

As you are learning how to scope a HarmonyOS migration correctly, you are not porting an app. You are building a second product that references the first. Budget, timeline, and team size need to reflect that from day one.

Where the Work Actually Piles Up 

Understanding the effort distribution before you start will prevent the most common under-scoping mistakes. Below is a clear table that can guide you on effort distribution at a glance. 

UI Migration (35 to 45% of Effort): 

This is consistently where teams spend more hours than they planned.

Android builds UIs imperatively using XML layouts. You define a view hierarchy in XML, then push state changes to individual views from code. Every update is manual.

ArkUI is fully declarative. You describe what the interface should look like based on the current state, and the current framework handles the rendering automatically.

ArkUI vs Android XML layout is not just a syntax difference; rather, a complete paradigm shift in how UI state, rendering, and component lifecycle are properly handled. 

Developers familiar with Jetpack Compose or SwiftUI adapt faster. Developers whose entire career is XML-based Android need 4 to 6 weeks to become productive with ArkUI.

The conversion gap in practice:

• Every Android screen needs individual reimplementation
• Custom components, Material Design elements, and Navigation Back Stacks all require their own ArkUI equivalents
• Animation definitions and seamless transition logic must be rebuilt

Huawei’s A2H Converter automates the XML-to-ArkUI conversion using the innovative AI-based layout mapping. It also helps achieve roughly 89% success on standard component conversions. On the other hand, the remaining 11% requires proper and manual intervention by skilled developers.

On a 200-screen application, that means approximately 22 screens need manual work after the pass. For apps with many custom components, the manual fallout rate also increases.

The A2H Converter path is still the fastest route for most projects. But it needs to be planned for explicitly. It is not a background task.

A real performance benefit worth noting: Taobao reported that its ArkUI-built checkout page runs 1.5 times faster than the Android equivalent. The migration has some significant performance upside, not just platform requirements.

Service Migration (30 to 40% of Effort): 

This phase is where unexpected blockers most often appear. Every Google service your Android app relies on needs a Huawei Mobile Services replacement. Some substitutions are straightforward. Others are not.

GMS to HMS Replacement Map

The harder problem is third-party SDKs with no HarmonyOS NEXT equivalent at all. Payment gateways without HMS support, analytics platforms without ArkTS SDKs, and niche API providers who have not updated for HarmonyOS NEXT all create hard blocks that require custom solutions.

Run a full dependency audit before migration begins. This takes 2 to 3 weeks and will prevent the most expensive surprises. Teams that skip this step routinely discover blocking dependencies right before a planned delivery date.

Language Learning (15-20% of effort):

ArkTS is the primary programming language for any HarmonyOS NEXT developer. It is built on TypeScript and keeps much of that familiar syntax, but it adds mandatory type annotations, HarmonyOS-specific APIs, concurrency controls, and custom decorators for state binding. 

Importantly, ArkTS is not a cross-platform web-view technology. Compiled ArkTS produces binary output. It properly runs on the device, not in a browser. This is a native language for native apps. 

Below is a timetable that might provide a view of the HarmonyOS development time estimate

Beyond language syntax, every HarmonyOS developer also needs to learn:

• DevEco Studio’s debugging and performance profiling tools
• HarmonyOS NEXT’s component lifecycle (different from Android Activity/Fragment model)
• The Hvigor build tool and the Ohpm package manager (both TypeScript/Node-based) 
• AppGallery Connect submission and review process
• HMS Kit integration patterns for each service have been replaced

Skipping this ramp-up estimate is one of the most common reasons that the first sprints dramatically underdeliver.

Real Effort Estimates 

These figures assume developers with solid mobile experience who are new to HarmonyOS NEXT. All costs use $80/hour as a reference rate for Asia-based contractors. 

Effort and Cost by App Type

Simple App (News Reader, Weather, Basic E-Commerce Catalogue)

Hours: 600 to 800 Timeline: around 3 to 4 months with 1 developer. Similarly, the Android to HarmonyOS migration cost also varies between $48,000 to $64,000.  

Where hours go on a simple app:

• UI rewrite: approximately 50%
• Service integration and backend connections: approximately 30%
• QA, device testing, and AppGallery review take approximately 20%

Note: AppGallery review takes almost 1 to 2 weeks and should be planned into the proper project schedule, not treated as a buffer at the end.

Medium Complexity App (Social, Messaging, Fitness Tracker, On-Demand)

The development hours may vary from 1,800 to 2,500 hrs for a medium complexity app. On the other hand, the timeline differs from 4 to 6 months, with 2 to 3 developers. Also, the cost for developing such apps may vary between $144,000 to $200,000. 

However, some additional complexity drivers at this tier are:

• Real-time data syncing and WebSocket handling
• Offline storage and handling sync logic
• Push notification integration with Huawei Push Kit
• Certain background services and scheduled task management
• Multi-device UI adaptation across different systems, such as – phone, tablet, and wearable

Each of these has HarmonyOS NEXT-specific implementation patterns. Furthermore, the budget research time also changes per feature, not just during the coding time.

Complex App (Banking, Enterprise, Gaming with Heavy Graphics)

The timing may vary: 4,000 or more. The timeline varies from 6 to 12 months, with 4 to 5 developers. Cost: $320,000 and above

The HarmonyOS migration effort for large apps compounds across multiple extra phases: 

• Security audit and penetration testing: 3 to 4 weeks
• China data residency compliance: 2 to 3 weeks
• Custom graphics pipeline rebuilds for games: 4 to 6 weeks
• Banking API and local payment system integration: 3 to 4 weeks
• Enterprise backend rearchitecting: varies

A useful benchmark: Organisations adopting HarmonyOS mini programs from scratch typically achieve 40 to 50% lower development costs compared to building separate native applications. This applies to greenfield builds only. Migrating from an existing Android codebase carries the full architectural complexity of the existing app and does not benefit from these savings in the same way.

The DevEco Studio Toolchain (What Helps and What Doesn’t)

DevEco Studio is Huawei’s one-stop integrated development environment for HarmonyOS app development. It is the required IDE for all HarmonyOS NEXT work, and it has improved significantly since the initial release.

Built on the JetBrains IDE platform, it delivers a familiar and comfortable experience for developers already used to working on IntelliJ IDEA or Android Studio.

What DevEco Studio includes:

• Visual layout designers with real-time device preview across phone, tablet, watch, and smart screen profiles
• ARM-based emulator for local testing
• Cloud-based emulator accessible from DevEco Studio’s Device Manager for developers based in China. Developers outside China currently have limited emulator options and typically rely on real devices for testing 
• Automated testing framework support
• Performance profiling tools for identifying rendering and memory issues
• Multi-language debugging for ArkTS, C++, and JavaScript (JetBrains toolchain support)
• Hvigor build tool for compiling and packaging HarmonyOS apps. It is TypeScript and Node-based, which makes it simpler to configure than Gradle, though build speeds can lag
• ohpm package manager for managing app dependencies, configured through oh-package.json5 files. Works similarly to npm but is scoped entirely to the HarmonyOS NEXT ecosystem
• Build a variant management comparable to Android’s products 

Where the toolchain still lags:

The IDE is functional. The support ecosystem behind it is not at Android Studio’s maturity level.

• Stack Overflow has years of indexed, verified Android answers. The HarmonyOS NEXT equivalent community is a fraction of that size.
• Official documentation quality has improved, but it still has some gaps. These gaps are prominent, particularly for certain scenarios like custom input methods, low-level audio pipeline control, and complex camera APIs.
• When you hit an undocumented edge case on Android, resolution typically takes hours. On HarmonyOS NEXT, the same problem can take days or require direct contact with Huawei developer support.

On a 4-month project, budget 2 to 4 weeks of absorbed effort for documentation gaps and slow support resolution cycles. This is not padding. It is the realistic cost of working on a maturing platform.

What You’ll Waste Time On (Hidden Costs)

Every HarmonyOS migration project goes through most of these. Plan for them ahead of time, or else you can discover them later or during the project. 

Testing Matrix Explosion

HarmonyOS NEXT runs across a wide range of devices. These include phones, tablets, wearables, smart screens, vehicle infotainment systems, and IoT devices. Device memory ranges from 128KB on low-end IoT hardware to 4GB on flagship phones.

This device diversification creates some real testing complexity:

• UI rendering and layout behaviour significantly differ
• Performance benchmarks vary significantly between different stages of a device 
• Background service handling, push notifications, and sensor APIs behave differently on different wearables, phones, and vehicles

Keep a budget of 20 to 30% additional time for device matrix testing, a significant step beyond the core development estimate. Android’s device fragmentation experience does not fully prepare teams for the range of HarmonyOS NEXT hardware categories.

A practical approach: define a primary device tier for QA (flagship phone, mid-range phone, tablet), then run exploratory testing on different wearable and smart screen target apps. 

Feature Gaps and Workarounds

As of August 2025, HarmonyOS 5.1.0 has some measurable gaps in conveying the best app experience compared to Android and iOS. Furthermore, popular apps, including Meituan and Bilibili, continue to lack some features even after months of their HarmonyOS NEXT launches. Some are less common and enterprise-built, but they still experience crashes and freezes.

What this means for scoping:

• You cannot fully scope a migration until coding begins
• Some features require some additional work, and some need to be postponed to Phase 2
• Committing to feature-complete equality at launch will produce either missed deadlines or even some unstable releases

Run a 2-week discovery sprint before locking timelines. Any estimate developed without one is a rough order, not a final commitment-ready number.

Library and SDK Gaps

Many Android libraries have no maintained HarmonyOS NEXT equivalent. When you encounter a missing library, the options are:

• Fork it and port to ArkTS
• Build a native wrapper against the HarmonyOS API
• Remove the feature that relied on it

Forking is viable for small utility libraries. It becomes expensive quickly for any library with a significant surface area.

A dependency audit before migration starts costs 2 to 4 weeks. Discovering a blocking library dependency 2 weeks before a planned delivery costs significantly more than that.

The Migration Paths (Pick Your Approach)

There is no single right path. Hence, the best approach always depends on your app’s architecture, codebase age, and how tightly you are planning to make it based on Android-specific patterns.

Path 1: Ground-Up Rewrite

This sounds like the most expensive option by the numbers. For some apps, it produces the cleanest result.

If your Android app’s architecture revolves around the Android lifecycle, is heavily dependent on Java patterns, or is built around Google service integrations, starting fresh in ArkTS would be a good choice. This step might help to avoid carrying those constraints into a new platform.

This Approach Is Recommended when:

• The app is 5 or more years old with a limited modular architecture
• Business logic is deeply entangled with Android-specific APIs
• Google service dependencies run through the core application code

Path 2: A2H Converter Plus Manual Service Migration

This is the most common path for how to develop an app for HarmonyOS from an existing Android codebase today. 

The A2H Converter handles the mechanical UI conversion work. Experienced HarmonyOS NEXT developers address the 11% manual fallout and handle the full service layer migration independently.

This Approach Is Recommended when:

• App has a layered and modular architecture
• UI components follow some significant and standard Android View patterns without any heavy customisation
• The team is building ArkTS expertise with seamless migration

Path 3: Mini Program or Web App Conversion

Huawei provides conversion utilities for WeChat mini programs and certain web app architectures. If meaningful functionality already exists in mini program format, this path offers the fastest and safest route to HarmonyOS NEXT availability.

This Approach Is Recommended when:

• App already has a mini program version
• Core functionality is achievable in a lightweight or web-based format
• Speed to market matters more than native feature depth

Timeline For Your Specific App Type

Below is a clear timeline that might guide you on the specific app type, allowing you to make the right choice. 

For a fitness app (medium complexity):

For a fintech app (high complexity):

Apps with multi-jurisdictional regulatory requirements or complex backend infrastructure should plan for 7 to 8 months minimum.

Get a Free HarmonyOS Migration Assessment

If you want a number you can actually build a business case around, the only reliable path is a codebase review first.

As you are looking for proper and detailed insights on how to migrate an Android app to HarmonyOS, a seamless assessment looks at your Android project’s screen count, component complexity, third-party dependency list, and service architecture. From that, you get an effort range with a confidence level attached, not a single number that breaks on first contact with the actual codebase.

Get a free HarmonyOS migration assessment. We review your Android codebase and give you an accurate estimate you can use.

How GMTA Can help You Migrate an Android app to HarmonyOS?

GMTA works on HarmonyOS app development and migration projects across different sectors such as fitness, e-commerce, logistics, and fintech verticals. 

Our migration process starts with the dependency audit and UI complexity assessment. From there, we build the phase plan, assign the right team size for the target timeline, and handle the full technical stack. These include –

• ArkUI rebuild
• HMS service integration
• DevEco Studio configuration
• AppGallery submission

For teams that have already started and hit blockers, our remediation work targets specific problems, such as missing SDK workarounds, test matrix coverage gaps, or ArkTS performance issues that actually emerged after initial development.

If you want to migrate Android to HarmonyOS, we do not produce single-point estimates that collapse under scrutiny. Every engagement we start requires a properly scoped assessment, so both sides know what they are actually going to get. 

Ready to start? Reach out to GMTA Software for a free codebase review and migration assessment.

FAQs 

Can I reuse my existing Kotlin or Java code on HarmonyOS NEXT?

No. HarmonyOS NEXT uses ArkTS as its primary language. Application-layer Kotlin and Java cannot be executed directly. In limited cases, C++ native code can be wrapped using HarmonyOS NEXT’s NDK, but all application logic must be rewritten in ArkTS.

Is HarmonyOS just Android with a different name?

No. HarmonyOS versions 1 through 4 ran on an Android compatibility layer. HarmonyOS NEXT (versions 5 and 6) is a clean-slate OS with its own kernel, runtime, and development stack. There is no Android runtime and no support for APKs.

What is the actual difference between ArkUI and Android XML layouts?

Android XML is imperative. You define a view hierarchy and manually push state updates to individual views. ArkUI is declarative; the framework handles rendering based on state. When you check the ArkUI vs Android XML layout, you will learn this is a full paradigm shift, comparable to moving from traditional View-based Android development to Jetpack Compose.

How long does AppGallery review take after submission?

1 to 2 weeks. Build this into your project schedule before committing to a launch date. Plan this into your overall project schedule, particularly if you have made some special launch-date commitments with your clients. 

Do I need a Chinese business entity to publish on AppGallery?

Not for general consumer apps. International developers can publish through AppGallery Connect with a standard Huawei developer account. Regulated categories such as finance, healthcare, and education may require a local entity to comply with Chinese regulatory requirements.

What is the minimum realistic timeline for any HarmonyOS migration?

12 weeks for a simple, well-architected app with one experienced HarmonyOS NEXT developer. This covers setup, development, testing, and AppGallery review. Compressing below this consistently produces technical debt that surfaces in the first maintenance release.

How is HarmonyOS app development different from Android development day to day?

Four core differences: the language (ArkTS vs Kotlin/Java), the UI system (declarative ArkUI vs imperative XML), the service layer (HMS vs GMS), and the toolchain (DevEco Studio vs Android Studio). Component lifecycle, state handling, and build configuration all work differently despite serving the same purpose.

Is HarmonyOS worth migrating to from a business perspective?

For China-focused apps, yes. The Android to HarmonyOS migration cost varies. HarmonyOS holds 18% market share in mainland China in 2025, ahead of iOS at 15%. AppGallery had 300,000 native apps by November 2025, and Huawei plans international expansion in 2026. The decision depends on whether your target market justifies the investment in migration.

Sourabh Singh

Sourabh Singh is Senior Developer at GMTA Software with 10+ years of experience building mobile and AI-powered applications across fintech, healthcare, and enterprise sectors. He has led 200+ app development projects and now focuses on helping businesses design and deploy scalable AI systems that deliver measurable ROI.