---
name: "up.Request.prototype.header"
area: "API"
kind: "Instance method"
parent: "up.Request class"
url: "https://unpoly.com/api/up.Request.prototype.header"
---
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# up.Request.prototype.header(name)

Returns the HTTP request header value with the given name.

Returns `undefined` if the given header name will not be sent with this request.

> #### Note
>
> For implementation reasons, the search for the header is case-sensitive.

---

## Parameters {#parameters}

### name {#name}

(required)

The case-sensitive name.

Type: string

---

## Return value {#return-value}

The value of the header.

Type: string | undefined