Invoke-WebRequest

Gets content from a web page on the Internet.

Syntax

Invoke-WebRequest
      [-UseBasicParsing]
      [-Uri] <Uri>
      [-WebSession <WebRequestSession>]
      [-SessionVariable <String>]
      [-Credential <PSCredential>]
      [-UseDefaultCredentials]
      [-CertificateThumbprint <String>]
      [-Certificate <X509Certificate>]
      [-UserAgent <String>]
      [-DisableKeepAlive]
      [-TimeoutSec <Int32>]
      [-Headers <IDictionary>]
      [-MaximumRedirection <Int32>]
      [-Method <WebRequestMethod>]
      [-Proxy <Uri>]
      [-ProxyCredential <PSCredential>]
      [-ProxyUseDefaultCredentials]
      [-Body <Object>]
      [-ContentType <String>]
      [-TransferEncoding <String>]
      [-InFile <String>]
      [-OutFile <String>]
      [-PassThru]
      [<CommonParameters>]

Description

The Invoke-WebRequest cmdlet sends HTTP, HTTPS, FTP, and FILE requests to a web page or web service. It parses the response and returns collections of forms, links, images, and other significant HTML elements.

This cmdlet was introduced in Windows PowerShell 3.0.

Note

By default, script code in the web page may be run when the page is being parsed to populate the ParsedHtml property. Use the -UseBasicParsing switch to suppress this.

Examples

Example 1: Send a web request

This command uses the Invoke-WebRequest cmdlet to send a web request to the Bing.com site.

$R = Invoke-WebRequest -URI http://www.bing.com?q=how+many+feet+in+a+mile
$R.AllElements | Where-Object {
    $_.name -like "* Value" -and $_.tagName -eq "INPUT"
} | Select-Object Name, Value

name       value
----       -----
From Value 1
To Value   5280

The first command issues the request and saves the response in the $R variable.

The second command filters the objects in the AllElements property where the name property is like "* Value" and the tagName is "INPUT". The filtered results are piped to Select-Object to select the name and value properties.

Example 2: Use a stateful web service

This example shows how to use the Invoke-WebRequest cmdlet with a stateful web service, such as Facebook.

$R = Invoke-WebRequest http://www.facebook.com/login.php -SessionVariable fb
# This command stores the first form in the Forms property of the $R variable in the $Form variable.
$Form = $R.Forms[0]
# This command shows the fields available in the Form.
$Form.fields

Key                     Value
---                     -----
...
email
pass
...

# These commands populate the username and password of the respective Form fields.
$Form.Fields["email"]="User01@Fabrikam.com"
$Form.Fields["pass"]="P@ssw0rd"
# This command creates the Uri that will be used to log in to facebook.
# The value of the Uri parameter is the value of the Action property of the form.
$Uri = "https://www.facebook.com" + $Form.Action
# Now the Invoke-WebRequest cmdlet is used to sign into the Facebook web service.
# The WebRequestSession object in the $FB variable is passed as the value of the WebSession parameter.
# The value of the Body parameter is the hash table in the Fields property of the form.
# The value of the *Method* parameter is POST. The command saves the output in the $R variable.
$R = Invoke-WebRequest -Uri $Uri -WebSession $FB -Method POST -Body $Form.Fields
$R.StatusDescription

The first command uses the Invoke-WebRequest cmdlet to send a sign-in request. The command specifies a value of "FB" for the value of the SessionVariable parameter, and saves the result in the $R variable. When the command completes, the $R variable contains an HtmlWebResponseObject and the $FB variable contains a WebRequestSession object.

After the Invoke-WebRequest cmdlet signs in to facebook, the StatusDescription property of the web response object in the $R variable indicates that the user is signed in successfully.

Example 3: Get links from a web page

This command gets the links in a web page.

(Invoke-WebRequest -Uri "http://msdn.microsoft.com/en-us/library/aa973757(v=vs.85).aspx").Links.Href

The Invoke-WebRequest cmdlet gets the web page content. Then the Links property of the returned HtmlWebResponseObject is used to display the Href property of each link.

Example 4: Catch non success messages from Invoke-WebRequest

When Invoke-WebRequest encounters a non-success HTTP message (404, 500, etc.), it returns no output and throws a terminating error. To catch the error and view the StatusCode you can enclose execution in a try/catch block. The following example shows how to accomplish this.

try
{
    $response = Invoke-WebRequest -Uri "www.microsoft.com/unkownhost" -ErrorAction Stop
    # This will only execute if the Invoke-WebRequest is successful.
    $StatusCode = $Response.StatusCode
}
catch
{
    $StatusCode = $_.Exception.Response.StatusCode.value__
}
$StatusCode

404

The first command calls Invoke-WebRequest with an ErrorAction of Stop, which forces Invoke-WebRequest to throw a terminating error on any failed requests. The terminating error is caught by the catch block which retrieves the StatusCode from the Exception object.

Parameters

-Body

Specifies the body of the request. The body is the content of the request that follows the headers. You can also pipe a body value to Invoke-WebRequest.

The Body parameter can be used to specify a list of query parameters or specify the content of the response.

When the input is a GET request and the body is an IDictionary (typically, a hash table), the body is added to the URI as query parameters. For other GET requests, the body is set as the value of the request body in the standard name=value format.

When the body is a form, or it is the output of an Invoke-WebRequest call, PowerShell sets the request content to the form fields.

Type:Object
Position:Named
Default value:None
Accept pipeline input:True (ByValue)
Accept wildcard characters:False
-Certificate

Specifies the client certificate that is used for a secure web request. Enter a variable that contains a certificate or a command or expression that gets the certificate.

To find a certificate, use Get-PfxCertificate or use the Get-ChildItem cmdlet in the Certificate (Cert:) drive. If the certificate is not valid or does not have sufficient authority, the command fails.

Type:X509Certificate
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-CertificateThumbprint

Specifies the digital public key certificate (X509) of a user account that has permission to send the request. Enter the certificate thumbprint of the certificate.Certificates are used in client certificate-based authentication. They can be mapped only to local user accounts; they do not work with domain accounts.

To get a certificate thumbprint, use the Get-Item or Get-ChildItem command in the PowerShell Cert: drive.

Type:String
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-ContentType

Specifies the content type of the web request.

If this parameter is omitted and the request method is POST, Invoke-WebRequest sets the content type to application/x-www-form-urlencoded. Otherwise, the content type is not specified in the call.

Type:String
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-Credential

Specifies a user account that has permission to send the request. The default is the current user.

Type a user name, such as User01 or Domain01\User01, or enter a PSCredential object, such as one generated by the Get-Credential cmdlet.

Type:PSCredential
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-DisableKeepAlive

Indicates that the cmdlet sets the KeepAlive value in the HTTP header to False. By default, KeepAlive is True. KeepAlive establishes a persistent connection to the server to facilitate subsequent requests.

Type:SwitchParameter
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-Headers

Specifies the headers of the web request. Enter a hash table or dictionary.

To set UserAgent headers, use the UserAgent parameter. You cannot use this parameter to specify UserAgent or cookie headers.

Type:IDictionary
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-InFile

Gets the content of the web request from a file.

Enter a path and file name. If you omit the path, the default is the current location.

Type:String
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-MaximumRedirection

Specifies how many times PowerShell redirects a connection to an alternate Uniform Resource Identifier (URI) before the connection fails. The default value is 5. A value of 0 (zero) prevents all redirection.

Type:Int32
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-Method

Specifies the method used for the web request. The acceptable values for this parameter are:

  • Default
  • Delete
  • Get
  • Head
  • Merge
  • Options
  • Patch
  • Post
  • Put
  • Trace
Type:WebRequestMethod
Accepted values:Default, Get, Head, Post, Put, Delete, Trace, Options, Merge, Patch
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-OutFile

Specifies the output file for which this cmdlet saves the response body. Enter a path and file name. If you omit the path, the default is the current location.

By default, Invoke-WebRequest returns the results to the pipeline. To send the results to a file and to the pipeline, use the Passthru parameter.

Type:String
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-PassThru

Indicates that the cmdlet returns the results, in addition to writing them to a file. This parameter is valid only when the OutFile parameter is also used in the command.

Type:SwitchParameter
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-Proxy

Specifies a proxy server for the request, rather than connecting directly to the Internet resource. Enter the URI of a network proxy server.

Type:Uri
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-ProxyCredential

Specifies a user account that has permission to use the proxy server that is specified by the Proxy parameter. The default is the current user.

Type a user name, such as User01 or Domain01\User01, or enter a PSCredential object, such as one generated by the Get-Credential cmdlet.

This parameter is valid only when the Proxy parameter is also used in the command. You cannot use the ProxyCredential and ProxyUseDefaultCredentials parameters in the same command.

Type:PSCredential
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-ProxyUseDefaultCredentials

Indicates that the cmdlet uses the credentials of the current user to access the proxy server that is specified by the Proxy parameter.

This parameter is valid only when the Proxy parameter is also used in the command. You cannot use the ProxyCredential and ProxyUseDefaultCredentials parameters in the same command.

Type:SwitchParameter
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-SessionVariable

Specifies a variable for which this cmdlet creates a web request session and saves it in the value. Enter a variable name without the dollar sign ($) symbol.

When you specify a session variable, Invoke-WebRequest creates a web request session object and assigns it to a variable with the specified name in your PowerShell session. You can use the variable in your session as soon as the command completes.

Unlike a remote session, the web request session is not a persistent connection. It is an object that contains information about the connection and the request, including cookies, credentials, the maximum redirection value, and the user agent string. You can use it to share state and data among web requests.

To use the web request session in subsequent web requests, specify the session variable in the value of the WebSession parameter. PowerShell uses the data in the web request session object when establishing the new connection. To override a value in the web request session, use a cmdlet parameter, such as UserAgent or Credential. Parameter values take precedence over values in the web request session.

You cannot use the SessionVariable and WebSession parameters in the same command.

Type:String
Aliases:SV
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-TimeoutSec

Specifies how long the request can be pending before it times out. Enter a value in seconds. The default value, 0, specifies an indefinite time-out.

A Domain Name System (DNS) query can take up to 15 seconds to return or time out. If your request contains a host name that requires resolution, and you set TimeoutSec to a value greater than zero, but less than 15 seconds, it can take 15 seconds or more before a WebException is thrown, and your request times out.

Type:Int32
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-TransferEncoding

Specifies a value for the transfer-encoding HTTP response header. The acceptable values for this parameter are:

  • Chunked
  • Compress
  • Deflate
  • GZip
  • Identity
Type:String
Accepted values:chunked, compress, deflate, gzip, identity
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-Uri

Specifies the Uniform Resource Identifier (URI) of the Internet resource to which the web request is sent. Enter a URI. This parameter supports HTTP, HTTPS, FTP, and FILE values.

This parameter is required.

Type:Uri
Position:0
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-UseBasicParsing

Indicates that the cmdlet uses the response object for HTML content without Document Object Model (DOM) parsing. This parameter is required when Internet Explorer is not installed on the computers, such as on a Server Core installation of a Windows Server operating system.

Type:SwitchParameter
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-UseDefaultCredentials

Indicates that the cmdet uses the credentials of the current user to send the web request.

Type:SwitchParameter
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-UserAgent

Specifies a user agent string for the web request. The default user agent is similar to Mozilla/5.0 (Windows NT; Windows NT 6.1; en-US) WindowsPowerShell/3.0 with slight variations for each operating system and platform.

To test a website with the standard user agent string that is used by most Internet browsers, use the properties of the PSUserAgent class, such as Chrome, FireFox, InternetExplorer, Opera, and Safari. For example, the following command uses the user agent string for Internet Explorer

Type:String
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False
-WebSession

Specifies a web request session. Enter the variable name, including the dollar sign ($).

To override a value in the web request session, use a cmdlet parameter, such as UserAgent or Credential. Parameter values take precedence over values in the web request session.

Unlike a remote session, the web request session is not a persistent connection. It is an object that contains information about the connection and the request, including cookies, credentials, the maximum redirection value, and the user agent string. You can use it to share state and data among web requests.

To create a web request session, enter a variable name (without a dollar sign) in the value of the SessionVariable parameter of an Invoke-WebRequest command. Invoke-WebRequest creates the session and saves it in the variable. In subsequent commands, use the variable as the value of the WebSession parameter.

You cannot use the SessionVariable and WebSession parameters in the same command.

Type:WebRequestSession
Position:Named
Default value:None
Accept pipeline input:False
Accept wildcard characters:False

Inputs

System.Object

You can pipe the body of a web request to Invoke-WebRequest.

Outputs

Microsoft.PowerShell.Commands.HtmlWebResponseObject