CWA vs PWA

Understanding the differences between Containerized Web Apps and Progressive Web Apps, and when to use each.

Overview

PWAs and CWAs are complementary technologies. Both use standard HTML, CSS, and JavaScript. PWAs run in the browser with progressive enhancement. CWAs run inside a native container that renders content using the platform's built-in WebView component (WKWebView / WebKit on iOS, Android WebView on Android) — the same rendering engines used by Safari and Chrome. The CWA container adds a permission-gated JavaScript bridge for native device APIs, while the content itself remains standard web content within the WebView sandbox. The same codebase can serve both — detect the bridge at runtime and unlock extra features.

Side-by-Side Comparison

Feature	PWA	CWA
Rendering Engine	Browser engine (varies)	Platform WebView (WKWebView/WebKit on iOS, Android WebView on Android)
Content Type	HTML / CSS / JS	HTML / CSS / JS only (no native code)
Distribution	Browser install prompt / URL	LoadSites container app
App Discovery	URL or app store listing	Enter domain in LoadSites
Installation	Service Worker + manifest.json	loadsites.app.manifest + ZIP bundle
Camera	MediaDevices API (limited)	Full native camera + gallery
Biometrics	WebAuthn (limited)	Face ID / Touch ID / fingerprint
Haptics	Vibration API (basic)	Impact, notification, custom duration
Push Notifications	Web Push API (free, browser-managed)	LoadSites Cloud relay (requires license)
Geolocation	Geolocation API	Native GPS with watch
Share	Web Share API (some browsers)	Native share sheet (all platforms)
Clipboard	Clipboard API (with permission)	Read/write clipboard
Offline Support	Service Worker cache	Entire app bundled locally as ZIP
Updates	Service Worker lifecycle	Manifest version check + ZIP swap
Storage	IndexedDB, localStorage	Bridge storage (native, persistent, scoped)
Multi-App per Domain	One PWA per scope	Multiple apps via manifest apps[]
Sandboxing	Browser same-origin policy	Domain + appId scoped storage + permissions
Bundle Size	No limit (fetched on demand)	50 MB max ZIP
Network Info	Network Information API (limited)	Real-time status + type changes
Device Info	Navigator API (limited)	Platform, model, OS version

When to Use CWA

CWA is the better choice when your app needs:

• Native device APIs — camera, biometrics, haptics that go beyond Web APIs
• Guaranteed offline — the entire app is pre-downloaded; no service worker complexity
• Multiple apps per domain — serve a suite of apps from a single domain
• App-switcher UX — users can switch between installed apps with a swipe gesture
• Consistent experience — same behavior across iOS and Android without browser differences

When to Use PWA

PWA is the better choice when:

• No install barrier — you want users to access the app directly via URL
• SEO matters — search engines can index PWAs directly
• Free push notifications — Web Push is free; CWA notifications require a license
• Desktop support — PWAs work on desktop browsers; CWA is mobile-focused
• Large dynamic content — apps that rely heavily on server-rendered content

Can You Use Both?

Yes. A single web app can be both a PWA and a CWA simultaneously. Detect the container at runtime and progressively enhance:

if (window.LoadSites) {
  // Running inside CWA container — use native APIs
  LoadSites.haptics.impact('medium');
  LoadSites.camera.takePhoto().then(handlePhoto);
} else if ('serviceWorker' in navigator) {
  // Running as PWA — use Web APIs
  navigator.vibrate(100);
  navigator.mediaDevices.getUserMedia({ video: true }).then(handleStream);
}

This pattern lets you maintain a single codebase that delivers the best experience on each platform. PWA users get a functional app, CWA users get enhanced native features.

Platform Compliance

Unlike PWAs, CWA apps are distributed through a native container app (LoadSites) available on the Apple App Store and Google Play. LoadSites complies with platform guidelines by rendering all CWA content exclusively through the system's native WebView (WKWebView / WebKit on iOS, as required by Apple Guideline 2.5.6). CWA bundles contain only static web assets (HTML, CSS, JavaScript, images, fonts). No native executable code, bytecode, or binaries are downloaded or executed. The bridge API is permission-gated, sandboxed, and does not expose raw platform APIs to loaded content.

See Compliance & Security for full details on Apple App Store and Google Play policy alignment.

Migrating a PWA to CWA

1. Keep your PWA — No need to remove your manifest.json or service worker. CWA works alongside PWA.
2. Create a CWA manifest — Add loadsites.app.manifest to your domain root. See Manifest Spec.
3. Bundle your build output — ZIP your dist/ or build/ folder and host it.
4. Add bridge detection — Check for window.LoadSites and use native APIs where available.
5. Test in LoadSites — Enter your domain in the LoadSites app and verify everything works.