# shwcs.net — what your browser can do

> A live reference for 80 modern web platform capabilities. Every page probes your browser in real time and lets you try the API. All checks run locally; nothing is sent anywhere.

## Capabilities by category

### 📱 PWA & Install
- [Install Prompt](https://www.shwcs.net/capability/install-prompt): Prompt visitors to install this site as an app.
- [Web App Manifest](https://www.shwcs.net/capability/web-app-manifest): Metadata that makes a site installable: name, icons, display mode.
- [Service Worker](https://www.shwcs.net/capability/service-worker): Programmable network proxy enabling offline and background features.
- [Offline Support](https://www.shwcs.net/capability/offline-ready): Service worker + Cache API together make this site work offline.
- [App Badging](https://www.shwcs.net/capability/badging): Show a badge count on the installed app icon.
- [App Shortcuts](https://www.shwcs.net/capability/app-shortcuts): Jump-list entries on the installed app icon (manifest `shortcuts`). Runtime-probed via install-prompt proxy.
- [Share Target](https://www.shwcs.net/capability/share-target): Receive shares from other apps into this PWA (manifest `share_target`). Runtime-probed via install-prompt proxy.
- [File Handling](https://www.shwcs.net/capability/file-handlers): Register the installed app as a handler for file types.
- [Protocol Handling](https://www.shwcs.net/capability/protocol-handlers): Register as handler for custom URL schemes (`web+…`).
- [Window Controls Overlay](https://www.shwcs.net/capability/window-controls-overlay): Draw into the title-bar area of the installed desktop app.

### 💾 Storage & Files
- [Origin Private File System](https://www.shwcs.net/capability/opfs): A private, origin-scoped filesystem with fast synchronous access from workers.
- [IndexedDB](https://www.shwcs.net/capability/indexeddb): Transactional object database for large structured data.
- [Cache Storage](https://www.shwcs.net/capability/cache-api): Store request/response pairs — the backbone of offline apps.
- [Storage Quota & Persistence](https://www.shwcs.net/capability/storage-quota): Inspect how much you can store and request persistent (non-evictable) storage.
- [File System Access](https://www.shwcs.net/capability/file-system-access): Open and save real files on the user's disk via native pickers.
- [Compression Streams](https://www.shwcs.net/capability/compression-streams): Gzip/deflate compression and decompression as native streams.

### 🔌 Device Access
- [Web Bluetooth](https://www.shwcs.net/capability/web-bluetooth): Connect to Bluetooth LE devices and read/write GATT characteristics.
- [WebUSB](https://www.shwcs.net/capability/webusb): Talk to USB devices directly from the page.
- [Web Serial](https://www.shwcs.net/capability/web-serial): Read/write serial ports — Arduinos, printers, industrial gear.
- [WebHID](https://www.shwcs.net/capability/webhid): Communicate with human-interface devices beyond keyboard/mouse.
- [Web NFC](https://www.shwcs.net/capability/web-nfc): Read and write NFC tags (Android only).
- [Web MIDI](https://www.shwcs.net/capability/web-midi): Connect MIDI instruments and controllers.
- [Gamepad](https://www.shwcs.net/capability/gamepad): Read connected game controllers: buttons, axes, rumble.
- [Keyboard Lock](https://www.shwcs.net/capability/keyboard-lock): Capture system keys (Esc, Alt-Tab) in fullscreen.
- [Pointer Lock](https://www.shwcs.net/capability/pointer-lock): Unlimited relative mouse movement for games and 3D.

### 🧭 Sensors & Location
- [Geolocation](https://www.shwcs.net/capability/geolocation): Current position and continuous location watching.
- [Device Orientation & Motion](https://www.shwcs.net/capability/device-orientation): Tilt, rotation and acceleration events from the device.
- [Accelerometer](https://www.shwcs.net/capability/accelerometer): Generic Sensor API accelerometer readings.
- [Gyroscope](https://www.shwcs.net/capability/gyroscope): Angular velocity around three axes.
- [Magnetometer](https://www.shwcs.net/capability/magnetometer): Magnetic field readings — a compass.
- [Ambient Light Sensor](https://www.shwcs.net/capability/ambient-light): Environmental light level in lux.
- [Compute Pressure](https://www.shwcs.net/capability/compute-pressure): Observe CPU pressure to adapt workloads.

### 🎥 Media & Capture
- [Camera & Microphone](https://www.shwcs.net/capability/get-user-media): Capture live camera and microphone streams.
- [Screen Capture](https://www.shwcs.net/capability/screen-capture): Capture a tab, window or the whole screen.
- [MediaRecorder](https://www.shwcs.net/capability/media-recorder): Record audio/video streams to files.
- [Picture-in-Picture](https://www.shwcs.net/capability/picture-in-picture): Pop videos out into a floating always-on-top window.
- [Document Picture-in-Picture](https://www.shwcs.net/capability/document-pip): A floating window with arbitrary HTML content.
- [Media Session](https://www.shwcs.net/capability/media-session): Integrate with OS media controls and lock-screen UI.
- [Barcode Detection](https://www.shwcs.net/capability/barcode-detection): Detect QR codes and barcodes in images or camera frames.
- [Speech Synthesis](https://www.shwcs.net/capability/speech-synthesis): Text-to-speech with system voices.
- [Speech Recognition](https://www.shwcs.net/capability/speech-recognition): Speech-to-text from the microphone.
- [Web Audio](https://www.shwcs.net/capability/web-audio): Synthesize, process and analyze audio in real time.
- [WebCodecs](https://www.shwcs.net/capability/webcodecs): Low-level access to hardware video/audio encoders and decoders.

### 🎮 Graphics & Compute
- [WebGL 2](https://www.shwcs.net/capability/webgl): Hardware-accelerated 3D rendering.
- [WebGPU](https://www.shwcs.net/capability/webgpu): Modern GPU API for rendering and compute shaders.
- [OffscreenCanvas](https://www.shwcs.net/capability/offscreen-canvas): Render canvases from workers, off the main thread.
- [WebAssembly](https://www.shwcs.net/capability/webassembly): Near-native execution of compiled code.
- [Web Workers](https://www.shwcs.net/capability/web-workers): Run scripts on background threads.
- [SharedArrayBuffer & Cross-Origin Isolation](https://www.shwcs.net/capability/shared-array-buffer): Shared memory between threads — requires COOP/COEP headers.

### 📡 Communication & Background
- [WebRTC](https://www.shwcs.net/capability/webrtc): Peer-to-peer audio, video and data channels.
- [WebSocket](https://www.shwcs.net/capability/websocket): Bidirectional persistent connection to a server.
- [WebTransport](https://www.shwcs.net/capability/webtransport): Low-latency client-server messaging over HTTP/3.
- [Notifications](https://www.shwcs.net/capability/notifications): System notifications from the page.
- [Push Messages](https://www.shwcs.net/capability/push): Server-sent push messages, even when the page is closed.
- [Background Sync](https://www.shwcs.net/capability/background-sync): Defer work until connectivity returns.
- [Background Fetch](https://www.shwcs.net/capability/background-fetch): Large downloads/uploads that outlive the page.
- [Periodic Background Sync](https://www.shwcs.net/capability/periodic-sync): Periodically refresh content in the background.
- [BroadcastChannel](https://www.shwcs.net/capability/broadcast-channel): Message all same-origin tabs and workers.

### 🖥️ OS Integration
- [Async Clipboard](https://www.shwcs.net/capability/async-clipboard): Read and write text and images to the system clipboard.
- [Web Share](https://www.shwcs.net/capability/web-share): Open the native share sheet with text, links or files.
- [Screen Wake Lock](https://www.shwcs.net/capability/wake-lock): Keep the screen awake while the page is visible.
- [Vibration](https://www.shwcs.net/capability/vibration): Trigger haptic vibration patterns (mobile).
- [Battery Status](https://www.shwcs.net/capability/battery): Charge level and charging state.
- [Network Information](https://www.shwcs.net/capability/network-info): Connection type, downlink estimate, save-data hint.
- [Idle Detection](https://www.shwcs.net/capability/idle-detection): Detect when the user goes idle or locks the screen.
- [Fullscreen](https://www.shwcs.net/capability/fullscreen): Take any element fullscreen.
- [Screen Orientation](https://www.shwcs.net/capability/screen-orientation): Read — and on mobile, lock — the screen orientation.
- [EyeDropper](https://www.shwcs.net/capability/eyedropper): Pick a color from anywhere on the screen.
- [Local Font Access](https://www.shwcs.net/capability/local-fonts): Enumerate fonts installed on the system.
- [Window Management](https://www.shwcs.net/capability/window-management): Multi-screen awareness and cross-screen window placement.
- [Contact Picker](https://www.shwcs.net/capability/contact-picker): Let the user share contacts from their address book (mobile).

### 🔐 Identity & Payments
- [WebAuthn / Passkeys](https://www.shwcs.net/capability/webauthn): Passwordless sign-in with platform authenticators and passkeys.
- [Credential Management](https://www.shwcs.net/capability/credential-management): Store and retrieve credentials via the browser.
- [Payment Request](https://www.shwcs.net/capability/payment-request): Native payment sheets — Apple Pay, Google Pay and cards.
- [Federated Credential Management](https://www.shwcs.net/capability/fedcm): Privacy-preserving federated login without third-party cookies.

### ✨ Modern UI
- [View Transitions](https://www.shwcs.net/capability/view-transitions): Animated transitions between DOM states and pages.
- [Popover](https://www.shwcs.net/capability/popover): Built-in top-layer popovers with light dismiss — no JS library.
- [Dialog Element](https://www.shwcs.net/capability/dialog): Native modal dialogs with focus trapping and backdrop.
- [Scroll-Driven Animations](https://www.shwcs.net/capability/scroll-driven-animations): Animations driven by scroll position, off the main thread.
- [Speculation Rules](https://www.shwcs.net/capability/speculation-rules): Prerender likely next pages for instant navigation.

## Machine-readable knowledge

- [Open Knowledge Format bundle](https://www.shwcs.net/okf/index.md): the full capability knowledge base as OKF v0.1 markdown concepts.