---
title: allHTTPHeaderFields
framework: foundation
role: symbol
role_heading: Instance Property
path: foundation/nsmutableurlrequest/allhttpheaderfields
---

# allHTTPHeaderFields

A dictionary containing all of the HTTP header fields for a request.

## Declaration

```swift
var allHTTPHeaderFields: [String : String]? { get set }
```

## Discussion

Discussion Certain header fields are reserved (see Reserved HTTP headers). Do not use this property to set such headers.

## See Also

### Accessing header fields

- [addValue(_:forHTTPHeaderField:)](foundation/nsmutableurlrequest/addvalue(_:forhttpheaderfield:).md)
- [setValue(_:forHTTPHeaderField:)](foundation/nsmutableurlrequest/setvalue(_:forhttpheaderfield:).md)