VBScript SetRequestHeader Method

last modified April 9, 2025

The SetRequestHeader method in VBScript is part of the XMLHTTP object. It sets the value of an HTTP header to be sent with a request. This method must be called after calling open but before send. It allows customization of HTTP requests with specific headers.

SetRequestHeader is essential for API interactions and web scraping. It enables sending authentication tokens, content types, and custom headers. This tutorial covers SetRequestHeader with practical examples to demonstrate its usage.

SetRequestHeader Method Overview

The SetRequestHeader method takes two parameters: the header name and its value. It doesn't return any value. The method is available through the XMLHTTP object in VBScript for making HTTP requests.

Key features include setting standard and custom HTTP headers. Headers must be set after opening the connection but before sending. Multiple headers can be set for a single request. Understanding this method helps create robust web clients.

Basic Header Setting

This example demonstrates the simplest use of SetRequestHeader to set a Content-Type header. It shows how to prepare a POST request with JSON content. The header informs the server about the data format being sent.

basic_header.vbs

Set http = CreateObject("MSXML2.XMLHTTP")
http.Open "POST", "https://api.example.com/data", False
http.SetRequestHeader "Content-Type", "application/json"
http.Send "{""name"":""John""}"

WScript.Echo http.responseText

Set http = Nothing

The script creates an XMLHTTP object and opens a POST request. SetRequestHeader sets the Content-Type to application/json. The server will interpret the sent data as JSON. Finally, the response is displayed.

Setting Authorization Header

This example shows how to set an Authorization header for API authentication. Many web services require Bearer tokens or API keys in headers. The method ensures secure transmission of credentials.

auth_header.vbs

Set http = CreateObject("MSXML2.XMLHTTP")
http.Open "GET", "https://api.example.com/protected", False
http.SetRequestHeader "Authorization", "Bearer abc123xyz456"
http.Send

WScript.Echo http.status & " " & http.statusText

Set http = Nothing

The script sets an Authorization header with a Bearer token. This is common in OAuth2 authentication flows. The token grants access to protected resources. The response status indicates whether authentication succeeded.

Setting Multiple Headers

SetRequestHeader can be called multiple times to set several headers. This example shows setting both Content-Type and Accept headers. Different headers serve different purposes in HTTP communication.

multiple_headers.vbs

Set http = CreateObject("MSXML2.XMLHTTP")
http.Open "GET", "https://api.example.com/users", False
http.SetRequestHeader "Content-Type", "application/json"
http.SetRequestHeader "Accept", "application/json"
http.SetRequestHeader "X-Custom-Header", "MyValue"
http.Send

WScript.Echo http.responseText

Set http = Nothing

Three headers are set: Content-Type, Accept, and a custom header. Content-Type describes sent data, Accept specifies preferred response format. Custom headers enable additional server-side processing. Each header is set with a separate call.

Setting User-Agent Header

This example demonstrates setting the User-Agent header to identify the client. Some servers require specific User-Agent values or block unknown agents. The header helps servers tailor responses to client capabilities.

user_agent.vbs

Set http = CreateObject("MSXML2.XMLHTTP")
http.Open "GET", "https://www.example.com", False
http.SetRequestHeader "User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64)"
http.Send

WScript.Echo http.responseText

Set http = Nothing

The script sets a common browser User-Agent string. This can help avoid being blocked as a bot. The string identifies the client as Windows 10 with 64-bit architecture. Servers may serve different content based on User-Agent.

Setting Custom Headers

Custom headers allow sending application-specific data with requests. This example shows setting a custom X-Request-ID header. Such headers are often used for tracking requests through systems.

custom_header.vbs

Set http = CreateObject("MSXML2.XMLHTTP")
http.Open "POST", "https://api.example.com/log", False
http.SetRequestHeader "X-Request-ID", "123e4567-e89b-12d3-a456-426614174000"
http.SetRequestHeader "X-API-Version", "2.0"
http.Send "Test message"

WScript.Echo "Request completed with ID"

Set http = Nothing

Two custom headers are set: X-Request-ID with a UUID and X-API-Version. These headers don't affect HTTP protocol behavior but are processed by the application. Custom headers typically start with X- to avoid conflicts with standard headers.

Source

XMLHTTP Documentation

In this article, we have explored the SetRequestHeader method in VBScript, covering its usage and practical applications. From basic content types to custom headers, these examples demonstrate flexible HTTP request customization. With this knowledge, you can enhance your web interaction scripts.

Author

My name is Jan Bodnar and I am a passionate programmer with many years of programming experience. I have been writing programming articles since 2007. So far, I have written over 1400 articles and 8 e-books. I have over eight years of experience in teaching programming.

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