The navigator read-only property of the WorkerGlobalScope interface returns the WorkerNavigator associated with the worker. It is a specific navigator object, mostly a subset of the Navigator for browsing scopes, but adapted to workers.

A WorkerNavigator object.

If you call the following

console.log(navigator);

inside a worker (which would basically be the equivalent of self.console.log(self.navigator);, as these are being called on the worker scope, which can be referenced with WorkerGlobalScope.self), you will get a WorkerNavigator object written to the console — something like the following:

Object {onLine: true, userAgent: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_1) Ap…ML, like Gecko) Chrome/40.0.2214.93 Safari/537.36", product: "Gecko", platform: "MacIntel", appVersion: "5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKi…ML, like Gecko) Chrome/40.0.2214.93 Safari/537.36"…}
    appCodeName: "Mozilla"
    appName: "Netscape"
    appVersion: "5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.93 Safari/537.36"
    hardwareConcurrency: 4
    onLine: true
    platform: "MacIntel"
    product: "Gecko"
    userAgent: "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/40.0.2214.93 Safari/537.36"
    __proto__: Object

You could use this navigator object to return more information about the runtime environment, as you might do with a normal Navigator object.