ServiceWorkerRegistration: active property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨April 2018⁩.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

Note: This feature is available in Web Workers.

The active read-only property of the ServiceWorkerRegistration interface returns a service worker whose ServiceWorker.state is activating or activated. This property is initially set to null.

An active worker controls a Client if the client's URL falls within the scope of the registration (the scope option set when ServiceWorkerContainer.register is first called.)

Note: Once an active worker is activating, neither a runtime script error nor a force termination of the active worker prevents the active worker from getting activated.