What is browser feature detection?
Feature detection tests whether a browser supports a specific API, object, or property before attempting to run it. Instead of brittle browser sniffing (reading User-Agent strings), feature detection inspects runtime capabilities directly, ensuring resilience across engine updates and hardware differences.
How the feature score works
The feature score aggregates 100 possible points distributed across critical performance milestones:
| Category | Weight | Key Features Tested |
|---|---|---|
| Graphics & Compute | 30 pts | WebGPU, WebGL2, OffscreenCanvas |
| Assembly & Performance | 25 pts | WebAssembly, SIMD, Web Workers, SharedArrayBuffer |
| Media & Streaming | 20 pts | WebCodecs, Media Source Extensions, Web Audio API |
| Storage & Files | 15 pts | Origin Private File System (OPFS), IndexedDB, Storage Quota |
| Device & PWA | 10 pts | Service Workers, Push API, Web Bluetooth, WebHID |
Next-gen graphics: WebGPU and OffscreenCanvas
WebGPU is the successor to WebGL, exposing low-overhead access to modern GPU pipelines for rendering complex geometry and performing parallel mathematical compute shaders directly inside the browser sandbox. Combined with OffscreenCanvas, graphics rendering can be offloaded entirely to web background threads.
WebAssembly SIMD and Threads
WebAssembly (Wasm) executes near-native machine code in the browser. SIMD (Single Instruction, Multiple Data) operations process vectors of numbers simultaneously, delivering substantial speedups for client-side video transcoding, audio synthesis, gaming physics, and in-browser machine learning inference.
Modern Storage: OPFS and Quotas
The Origin Private File System (OPFS) provides direct, private, high-performance file access for web applications, enabling desktop-class databases like SQLite to run natively inside the browser tab with zero installation.
PWA and Background Capabilities
Progressive Web App APIs such as Service Workers, Cache Storage, and Background Synchronization allow web apps to load instantly offline, handle background events, and operate seamlessly as native-style system applications.
Frequently Asked Questions
Why does WebGPU show as unsupported even on modern browsers?
WebGPU requires compatible graphics hardware and operating system drivers. On virtual machines or systems with disabled hardware acceleration flags, WebGPU may be disabled by the browser.
Why is SharedArrayBuffer sometimes unavailable?
For security reasons following Spectre vulnerabilities, SharedArrayBuffer requires cross-origin isolation headers (COOP and COEP) served by the web host.
Does this audit track or transmit my computer specs?
No. All checks are executed locally using standard JavaScript inspection, and results are only stored in your browser's private local storage.