demo · v132

Probe cross-origin isolation gated APIs live

DIP is supposed to flip crossOriginIsolated on for the document. That unlocks SharedArrayBuffer, performance.measureUserAgentSpecificMemory(), and high-resolution timers. This page actually invokes each one and reports the truth.

window.crossOriginIsolated

overall feature flag — if true, COI-gated APIs are available

SharedArrayBuffer constructor

constructible only in cross-origin-isolated contexts

performance.measureUserAgentSpecificMemory()

heap-walk telemetry, COI-gated

performance.timeOrigin precision

5 microsecond vs 100 microsecond resolution

try invoking

new SharedArrayBuffer(1024)
performance.measureUserAgentSpecificMemory()
new Worker() + postMessage(SharedArrayBuffer)
click a "try" button
To enable Document-Isolation-Policy serve this page with Document-Isolation-Policy: isolate-and-credentialless. The static showcase doesn't set this header, so most probes will read false — the demo still surfaces the truth.

see also