Comparison#

OneJS uses Unity as a cross-platform runtime, giving you React development with GPU-accelerated rendering across desktop, mobile, web, and XR.

Bundle Sizes#

OneJS bundle size varies by platform since it includes the Unity runtime:

Platform	OneJS	Notes
WebGL	3-5 MB	Browser handles JS execution
Android	~35 MB	Includes IL2CPP runtime
iOS	~40 MB	Similar to Android
Desktop	~75 MB	Full standalone runtime

These sizes depend on Unity version and included features. Stripping unused code reduces them further.

	Electron	Tauri	Flutter	React Native	OneJS
Bundle size	100-150 MB	3-10 MB	5-40 MB	4-25 MB	3-75 MB
Rendering	CPU (Chromium)	System webview	Skia (GPU)	Native views	GPU (UI Toolkit)
Desktop	✓	✓	✓	Limited	✓
Mobile	✗	Beta	✓	✓	✓
Web	✗	✗	✓	✗	✓
VR/AR	✗	✗	✗	✗	✓
3D support	WebGL only	WebGL only	Limited	Limited	Full engine
Language	JS/TS	JS/TS + Rust	Dart	JS/TS	JS/TS
Consistency	High	Varies	High	Varies	High

OneJS size is platform-dependent: WebGL ~5MB, mobile ~35MB, desktop ~75MB.

Electron: Desktop-only apps where download size doesn't matter. Mature ecosystem.

Tauri: Smallest desktop bundles. Accept webview inconsistencies across platforms.

Flutter: Mobile-first apps. Willing to learn Dart.

React Native: Mobile apps with native UI components. Desktop is secondary.

OneJS: Cross-platform including XR. Need 3D capabilities. Want React with GPU rendering.

Traditional game UI (C#/C++) means slow iteration and verbose code. OneJS brings:

Declarative components instead of imperative code:

// OneJS
function MainMenu() {
    return <Button text="Play" onClick={handlePlay} />
}

// Traditional C#
var button = new Button();
button.text = "Play";
button.clicked += OnPlayClicked;
container.Add(button);

Hot reload: Change UI without recompiling or restarting play mode.

Modding: Players can modify JavaScript UI without touching compiled code.

Web developer onboarding: React developers contribute immediately.

Native platforms: QuickJS interpreter (works on iOS and other platforms where JIT is prohibited)
WebGL: Browser's V8/SpiderMonkey with full JIT optimization

Unity's retained-mode UI system with flexbox layout, CSS-like styling, and GPU rendering. React's reconciler maps directly to UI Toolkit elements.