SharedArrayBuffer & Cross-Origin Isolation
Probing…SharedArrayBuffer & Cross-Origin Isolation is a web platform capability in the Graphics & Compute category. Shared memory between threads — requires COOP/COEP headers. Supported in Chromium 68+, Firefox 79+, and Safari 15.2+. Requires a secure context (HTTPS or localhost) and cross-origin isolation (COOP and COEP headers).
Try it
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Code
if (crossOriginIsolated) {
const sab = new SharedArrayBuffer(4)
const view = new Int32Array(sab)
worker.postMessage({ sab }) // shared, not copied
// inside the worker:
const view = new Int32Array(e.data.sab)
Atomics.add(view, 0, 1) // atomic write to shared memory
// main thread reads the same bytes:
Atomics.load(view, 0)
}Browser support
Frequently asked questions
Which browsers support SharedArrayBuffer & Cross-Origin Isolation?
Supported in Chromium 68+, Firefox 79+, and Safari 15.2+.
Does SharedArrayBuffer & Cross-Origin Isolation require HTTPS?
Yes. SharedArrayBuffer & Cross-Origin Isolation needs a secure context, so it only works over HTTPS (or on localhost during development).
What is SharedArrayBuffer & Cross-Origin Isolation used for?
Shared memory between threads — requires COOP/COEP headers.
Can I try SharedArrayBuffer & Cross-Origin Isolation in my browser?
Yes. shwcs.net runs a live SharedArrayBuffer & Cross-Origin Isolation demo that probes your current browser and lets you try the API. Everything runs locally — nothing is sent anywhere.