- Browser capabilities determine whether your system can run rich web applications like 3D graphics, local AI models, and offline-first PWAs.
- Universal web standards like WebAssembly and WebGL 2 are baseline capabilities shared across Chrome, Firefox, and Safari.
- WebGPU demands active underlying operating system driver support (Vulkan, Metal, or Direct3D 12) to return an actual hardware adapter.
- Peripheral APIs (Web Bluetooth, WebUSB, WebHID, Web Serial) are WICG incubator drafts supported mainly in Chromium, not universal W3C standards.
What are browser capabilities?
Modern web browsers function as rich application runtime engines. Beyond parsing HTML documents and cascading stylesheets, modern browsers execute compiled binary modules, route peer-to-peer media streams, and interface with graphics processing units.
How functional detection works
Checking if an object property exists on window or navigator is often insufficient. For example, navigator.gpu may exist in a browser, but the underlying system may lack an active Vulkan or Metal driver. A functional capability probe instantiates real modules—such as compiling an 8-byte WebAssembly binary or requesting an actual GPUAdapter—to confirm the capability is active and usable.
Modern graphics & computation
The modern successor to WebGL, exposing compute shaders and low-overhead pipelines designed for contemporary graphics hardware.
Next-gen graphics & local AICompact binary format that executes compiled C++, Rust, and Go code at near-native execution speeds inside the browser sandbox.
High-performance computingDirect low-level access to built-in hardware video decoders and encoders without software container overhead.
Ultra-low-latency streamingOrigin quotas vs disk space
Web applications store offline caches using IndexedDB and the Cache API. Under default conditions, storage is treated as temporary and can be purged if host disk space runs low. When checking storage limits via navigator.storage.estimate(), browsers report an approximate origin quota, not your computer's entire physical drive capacity.
Permissions and security sandbox
Capabilities that present user privacy or device security considerations operate under strict permissions models. High-risk features (such as microphone, camera, and geolocation) require explicit user consent, prevent automatic activation, and are restricted strictly to secure contexts (HTTPS).
Browser capabilities FAQ
What does the Core Platform Score measure?
The score measures 9 universally agreed W3C/WHATWG core application standards: WebAssembly, WebGL 2, WebGPU, WebCodecs, WebRTC, Service Workers, Web Workers, IndexedDB, and WebSockets. Device-specific APIs like Web Bluetooth and Web Serial are reported as informational extensions without docking points.
Why does WebGPU show as unsupported even if navigator.gpu exists?
The presence of navigator.gpu only confirms the browser interface is present. Our tester requests an actual GPU hardware adapter via navigator.gpu.requestAdapter(). If host drivers (Vulkan, Metal, or Direct3D 12) are missing, or if the flag is disabled, no adapter is returned.
Why does Safari or Firefox lack Web Bluetooth and Web Serial?
Web Bluetooth, WebUSB, WebHID, and Web Serial are WICG incubator proposals implemented primarily in Chromium. Apple and Mozilla have declined to ship them by default citing physical device attack surface and fingerprinting concerns.
What is the difference between origin storage quota and free disk space?
The storage estimate returns the quota allocated by the browser to this specific origin, often capped at a fraction of total disk capacity or randomized in private browsing modes to mitigate storage-based fingerprinting.
Builds and maintains PC Tester diagnostic utilities. Functional routines adhere to W3C Web Platform recommendations, WHATWG standards, and WICG incubator specifications.