Is Flutter Really the King of Performance? React Native’s New Architecture Has Something to Say

When it comes to cross-platform mobile development, performance It has always been one of the most important discussions between Original reaction and flutter. Flutter has long been lauded as the king of performance, but with… Recent architectural updates for React NativeThe story is not as one-sided as it was before. Let’s break it down.

Why React Native has traditionally performed less than Flutter

React Native and Flutter handle and communicate with the native layer very differently.

React Native (legacy architecture) in detail

Bridge problem

In the old React Native model, your app’s business logic was written in JavaScript, while the UI and platform APIs (buttons, navigation, camera, etc.) were in native code (Objective-C/Swift for iOS, Java/Kotlin for Android).
To connect these two worlds, I used React Native Bridge – A communication layer that passes messages back and forth between JavaScript and native modules.
These messages were necessary Sequential (converted to JSON or similar) before and after submission It has been deserialized On the other side.

How does flow work?

JavaScript theme ← Bridge ← Native modules (UI, APIs) ← Screen

• JavaScript handled the application logic and events.
• The bridge carries messages asynchronously.
• The original modules provided the user interface and implemented platform features.

Why have things slowed down?

• Sequencing cost → Each message (eg “Set button color to red”) had to be converted before sending.
• Asynchronous nature → Messages were queued, so heavy animation or scrolling caused delays.
• Assemble and wait → Messages were grouped for efficiency, but in UI-heavy applications, this caused frame drops.
• Different threads → JavaScript is running on one thread, and the UI is on another thread, making synchronization difficult.

Impact on performance

• UI heavy applications → Stuttering animations and gestures.
• The platform flips → iOS and Android behave differently sometimes.
• Complex integrals → More native APIs means more bridges, which increases the cost of performance.

👉 In short: The old bridge-based architecture was powerful but built with serialization, batches, and cross-threaded communications.

Architectural Flow (Old vs. Flutter):

Flutter structure in detail

Draw every pixel

Flutter apps are written in Dart, compiled into native machine code, and run by Flutter motor (C++).
Unlike React Native, Flutter does not depend on the platform’s native UI components. Instead, it is Displays every pixelUsing a GPU-optimized rendering engine (impeller ).

How does streaming work?

Arrow icon ← Flutter Motor ← Impeller (GPU Viewer) ← Skia Graphics ← Display

• Dart Code defines the user interface and logic.
• Flutter Engine translates widget trees into display instructions.
• Impeller + Skia handles GPU drawing (buttons, text, images, animation).
• The screen displays the same UI across iOS and Android.

Why is it faster?

• There is no bridge → There is no back and forth between JS and local.
• Single rendering pipeline → The entire UI is handled within the Flutter engine.
• Direct access to the GPU → Impeller ensures smooth 60fps+ rendering.
• Same widgets everywhere → Uniform UI behavior across platforms.

Real world impact

• Consistent fps → Predictable performance across devices.
• Smooth animation → No stuttering from moving between pages.
• Uniformity across platforms → iOS and Android look identical.
• It handles the heavy user interface with ease → Complex transitions and animations work smoothly.

Example scenario comparing Flutter and React Native (old)

Imagine an app that displays a list of 100 images:

• flutter: Draws everything live with the GPU-optimized renderer → smooth 60fps.
• Original (old) reaction:
• JavaScript calculates what to show.
• It sends instructions (such as “display the image at position X”) across the bridge.
• Citizen makes it.
• For many items, the back and forth is constant It slows things down→ Frame drops or delays.

👉 In short: Flutter achieves higher and more consistent performance because it controls the entire render pipeline. there There is no bridge Not relying on the operating system’s native UI elements, direct GPU optimization ensures smooth and predictable results across platforms.

“That’s why this has been the mantra for years: Flutter always wins with performance. But now, the new React Native architecture flips the script.”

React Native latest update: New bridgeless architecture

Facebook (Meta) fixed React Native using a New architectureTo address these issues. Update offers:

JavaScript → JSI → TurboModules/Fabric → Native Components → Display

1. JSI (JavaScript Interface)

• Old road: In the old bridge model, communication between JavaScript and the native language was done through serialized messages (often JSON). This caused delays and overhead.
• New Road (JSI) :
• JSI availability Direct accessBetween JavaScript and native objects.
• No need to serialize/deserialize – functions and data can be called directly.
• This makes implementation Faster and closer to the original speed.
• example : Instead of sending JSON instructions like { “action”: “openCamera” } via a bridge, JavaScript can now call openCamera() directly with native code.

✅ a result:Dramatically lower latency, smoother performance, and fewer dropped frames.

2. Turbo units

• Old road : The native modules (such as camera, geolocation, etc.) are eagerly loaded – meaning that all modules are initialized on startup, whether they are used or not.
• New method (Turbo units):
• Units are loaded Lazily(Only when needed).
• They use JSI, so JS can access them directly without bridge serialization.
• Improves startup time and reduces memory usage.
• example : If your app does not use Push Notifications until later, this module will not load on startup → launch the app faster.

✅ a result:Faster startup, lower memory consumption, and better runtime efficiency.

3. Canvas viewer

The Old Way (Bridge + Yoga) :

React Component → JS Thread → Shadow Tree (Yoga) → Bridge → Native UI Thread → UI Platform

• Write the components of the reaction (, ).
• React creates a virtual tree (JS representation of the UI).
• This tree is converted to a shadow tree, which is a lightweight version of the UI structure.
• Yoga works here to account for the layout (sizes, flexible positions, etc.).
• After Yoga calculates the layout, the instructions (such as width = 200, height = 50, x = 10, y = 20) must be serialized into JSON-like messages.
• Sent over the bridge (asynchronous, in batches).
• On the original side, they were deserialized back into original objects before rendering.
• It maps them to native UI components (UIButton on iOS, TextView on Android).
• Finally, it draws the user interface on the screen.

The serialization + deserialization step was the main source of overhead and UI lag.

Yoga → Live (JSI/Canvas) → Original.

• The shade tree is still there, and the yoga still calculates the layout.
• But now, there it is No JSON serializationAnymore.
• Instead, the shadow tree itself is shared directly between JavaScript and Native using a JSI (JavaScript Interface).
• Both JS and Native can access the same objects in memory (no conversion).
• example : Complex animations (such as swipe to delete) now update smoothly because JS and native UI are tightly synchronized with fewer jumps.

✅ a result:Smoother user interface, fewer frame drops, and improved animation handling.

4. Codgen

• Old road : Developers manually wrote bindings to connect JS to native modules. This was error-prone and often lacked qualitative security.
• New method (Codegen):
• Automatically generates boilerplate code for native links at build time.
• Guaranteed Type secure connectionBetween JS and native.
• Reduces human errors and inconsistencies between platforms.
• example : If the native function expects an integer but JS sends a string, Codegen catches it at compile time.

✅ a result: A safer, more reliable and faster development workflow.

Architectural flow (new architecture):

This non-integrated approach significantly reduces overhead and makes React Native’s performance much closer to that of Flutter.

Flutter vs. Native Reaction: Performance Today

• flutter: It still has the advantage in raw GPU rendering because it controls every pixel and completely bypasses native tools.
• React original (new): Now provides near-native performance with Lower latency, better memory efficiency, and smoother UI updatesThanks to the fabric and turbo units.

In practice:

• For applications with Heavy custom graphics/animationsFlutter may still perform better.
• For applications that rely heavily on… Native integrations and platform-specific features React Native now competes aggressively without the old performance penalty.

Is the saying “flutter is always better” still true?

Not anymore.

Flutter still shines with its custom rendering engine and consistent UI performance. But the original reaction New architecture It changed the game – no more slow bridge, faster UI updates with Fabric, smarter native loading with TurboModules, and seamless, type-safe integration via Codegen.

Now, the original reactionHe delivers a performance that not only “comes close” – It redefines what cross-platform applications can achieve with JavaScript.

👉 So, the old saying “flutter is always better for performance” doesn’t apply anymore. With its update, React Native isn’t just catching up, it’s competing head-to-head.

conclusion

If your top priority is a pixel-perfect UI and complete display control, Flutter still holds the crown. But the story does not end there. With React Native New architectureThe discussion about performance is no longer a one-way street. React Native now stands shoulder to shoulder with Flutter, proving that it’s not only keeping pace, but competing at the highest level.

👉 The real truth in 2025: both frames Robust, battle-tested, and capable of building world-class applications. The old belief that “flutter always wins in performance” has become more of a myth than a reality.

Ultimately, your choice isn’t about who wins the performance race, it’s about what works for youYour team’s strengths, your project’s vision, and your long-term growth.

because “The future is not Flutter versus React Native, it is what you make with them.”