files/en-us/web/api/request/headers/index.md
{{APIRef("Fetch API")}}{{AvailableInWorkers}}
The headers read-only property of the
{{domxref("Request")}} interface contains the {{domxref("Headers")}} object associated
with the request.
A {{domxref("Headers")}} object.
In the following snippet, we create a new request using the {{domxref("Request.Request", "Request()")}} constructor (for an image file in the same directory as the script), then save the request headers in a variable:
const myRequest = new Request("flowers.jpg");
const myHeaders = myRequest.headers; // Headers {}
To add a header to the {{domxref("Headers")}} object we use
{{domxref("Headers.append")}}; we then create a new Request along with a
2nd init parameter, passing headers in as an init option:
const myHeaders = new Headers();
myHeaders.append("Content-Type", "image/jpeg");
const myInit = {
method: "GET",
headers: myHeaders,
mode: "cors",
cache: "default",
};
const myRequest = new Request("flowers.jpg", myInit);
const myContentType = myRequest.headers.get("Content-Type"); // returns 'image/jpeg'
{{Specifications}}
{{Compat}}