Fetch Headers

Working with Headers

The Headers class provides a case-insensitive, iterable interface to request and response headers.

Example

const headers = new Headers({
  "Content-Type": "application/json",
  "Authorization": `Bearer ${token}`,
});
headers.append("X-Request-Id", crypto.randomUUID());
const res = await fetch("/api/data", { headers });
res.headers.forEach((val, name) => console.log(name, val));

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Pro Tip

Header names are case-insensitive — Content-Type and content-type are the same header.

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