The priority read-only property of the Request interface contains the hinted priority of the request relative to other requests.

A USVString indicating the hinted priority of the request. Possible values are:

• high: Fetch the request at a high priority relative to other requests of a similar type.
• low: Fetch the request at a low priority relative to other requests of a similar type.
• auto: Default mode, which indicates no preference for the fetch priority. The browser decides what is best for the user.

In the following snippet, we create a new request using the Request() constructor (for an API endpoint) at a low priority, then save the priority of the request in a variable:

var myRequest = new Request('/background-api-call', {priority: 'low'});
var myPriority = myRequest.priority; // "low"

• ServiceWorker API
• HTTP access control (CORS)
• HTTP