System / 03

Capabilities.

Probes 25+ modern Web APIs in one shot: WebGPU, WebUSB, WebHID, Web Bluetooth, Wake Lock, File System Access, BarcodeDetector, and the rest.

How it works

Each API is checked with the cheapest possible probe: typeof X !== "undefined", X in navigator, or for WebGL / WebGL2 actually creating a canvas context. No permission prompts are triggered.

A 'yes' here doesn't guarantee the feature works flawlessly — some APIs are exposed but gated behind enterprise policy, OS support, or specific hardware (e.g., Web Bluetooth needs a Bluetooth chip). Use this as a starting filter, then test the specific feature you need.

Related
Codec matrix
Which audio / video codecs play in this browser.
Permissions
Per-API permission state: granted, denied, prompt.
User agent + hints
Decoded UA-CH for feature-detection logic.
Frequently asked

Why does this matter?

Web app developers and serious browser users want to know which modern APIs are wired up. A reader who's checking can confirm whether their browser version + OS combo enables the features they need — without trawling caniuse.com for 25 separate checks.

Why does Firefox say no to so many APIs?

Firefox has historically been more conservative with hardware-access APIs (WebUSB, WebSerial, Web Bluetooth) on philosophical grounds — they view those as fingerprinting risks. Chromium browsers ship them. This isn't a Firefox bug, it's a deliberate policy difference.

Is WebGPU truly stable?

Chrome 113, Edge 113, Safari 18 — all marked stable. Firefox is still behind dom.webgpu.enabled. For consumer-facing apps, WebGPU is usable today as long as you have a WebGL fallback for the 20-30% of users on Firefox or older browsers.

Why is SharedArrayBuffer often false?

Spectre / Meltdown mitigations require strict COOP/COEP headers before the browser exposes SharedArrayBuffer. Pages without those headers see it as unavailable, even though the underlying engine supports it. That's a deployment issue, not a browser version issue.

Related tools in System
What is my…
Everything navigator exposes about your device.
User agent + hints
Decoded UA-CH: brand, architecture, model.
Codec matrix
Which video / audio codecs play here.
Permissions
Granted / denied / prompt state per API.
Fonts probe
Which common fonts are installed.