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HttpWebRequest.Headers Property

Specifies a collection of the name/value pairs that make up the HTTP headers.

Namespace:  System.Net
Assembly:  System (in System.dll)

public override WebHeaderCollection Headers { get; set; }

Property Value

Type: System.Net.WebHeaderCollection
A WebHeaderCollection that contains the name/value pairs that make up the headers for the HTTP request.


The request has been started by calling the GetRequestStream, BeginGetRequestStream, GetResponse, or BeginGetResponse method.

The Headers collection contains the protocol headers associated with the request. The following table lists the HTTP headers that are not stored in the Headers collection but are either set by the system or set by properties or methods.


Set by


Set by the Accept property.


Set by the Connection property and KeepAlive property.


Set by the ContentLength property.


Set by the ContentType property.


Set by the Expect property.


Set by the Date property.


Set by the Host property.


Set by the IfModifiedSince property.


Set by the AddRange method.


Set by the Referer property.


Set by the TransferEncoding property (the SendChunked property must be true).


Set by the UserAgent property.

The Add method throws an ArgumentException if you try to set one of these protected headers.

Changing the Headers property after the request has been started by calling GetRequestStream, BeginGetRequestStream, GetResponse, or BeginGetResponse method throws an InvalidOperationException.

You should not assume that the header values will remain unchanged, because Web servers and caches may change or add headers to a Web request.

The following code example uses the Headers property to print the HTTP header name/value pairs to the console.

			// Create a new 'HttpWebRequest' Object to the mentioned URL.
			HttpWebRequest myHttpWebRequest=(HttpWebRequest)WebRequest.Create("");
			// Assign the response object of 'HttpWebRequest' to a 'HttpWebResponse' variable.
			HttpWebResponse myHttpWebResponse=(HttpWebResponse)myHttpWebRequest.GetResponse();
			Console.WriteLine("\nThe HttpHeaders are \n\n\tName\t\tValue\n{0}",myHttpWebRequest.Headers);
			// Print the HTML contents of the page to the console. 
			Stream streamResponse=myHttpWebResponse.GetResponseStream();
			StreamReader streamRead = new StreamReader( streamResponse );
			Char[] readBuff = new Char[256];
			int count = streamRead.Read( readBuff, 0, 256 );
			Console.WriteLine("\nThe HTML contents of page the are  : \n\n ");	
			while (count > 0) 
				String outputData = new String(readBuff, 0, count);
				count = streamRead.Read(readBuff, 0, 256);
			// Close the Stream object.
			// Release the HttpWebResponse Resource.

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.