The URLRequest class captures all of the information in a single HTTP request. URLRequest objects are passed to the load() methods of the Loader, URLStream, and URLLoader classes, and to other loading operations, to initiate URL downloads. They are also passed to the upload() and download() methods of the FileReference class.

A SWF file in the local-with-filesystem sandbox may not load data from, or provide data to, a resource that is in the network sandbox.

By default, the calling SWF file and the URL you load must be in the same domain. For example, a SWF file at can load data only from sources that are also at To load data from a different domain, place a URL policy file on the server hosting the data.

However, in Adobe AIR, content in the application security sandbox (content installed with the AIR application) is not restricted by these security limitations. For content running in Adobe AIR, files in the application security sandbox can access URLs using any of the following URL schemes:

  • http and https
  • file
  • app-storage
  • app

Content running in Adobe AIR that is not in the application security sandbox observes the same restrictions as content running in the browser (in Flash Player), and loading is governed by the content's domain and any permissions granted in URL policy files.

For more information related to security, see the Flash Player Developer Center Topic: Security.


new (?url:String)

Creates a URLRequest object. If System.useCodePage is true, the request is encoded using the system code page, rather than Unicode. If System.useCodePage is false, the request is encoded using Unicode, rather than the system code page.



The URL to be requested. You can set the URL later by using the url property.



The MIME content type of the content in the the data property.

The default value is application/x-www-form-urlencoded.

Note:The FileReference.upload(),, and HTMLLoader.load() methods do not support the URLRequest.contentType property.

When sending a POST request, the values of the contentType and data properties must correspond properly. The value of the contentType property instructs servers on how to interpret the value of the data property.

  • If the value of the data property is a URLVariables object, the value of contentType must be application/x-www-form-urlencoded.
  • If the value of the data property is any other type, the value of contentType should indicate the type of the POST data that will be sent(which is the binary or string data contained in the value of the data property).
  • For FileReference.upload(), the Content-Type of the request is set automatically to multipart/form-data, and the value of the contentType property is ignored.

In Flash Player 10 and later, if you use a multipart Content-Type(for example "multipart/form-data") that contains an upload(indicated by a "filename" parameter in a "content-disposition" header within the POST body), the POST operation is subject to the security rules applied to uploads:

  • The POST operation must be performed in response to a user-initiated action, such as a mouse click or key press.
  • If the POST operation is cross-domain(the POST target is not on the same server as the SWF file that is sending the POST request), the target server must provide a URL policy file that permits cross-domain access.

Also, for any multipart Content-Type, the syntax must be valid (according to the RFC2046 standards). If the syntax appears to be invalid, the POST operation is subject to the security rules applied to uploads.


An object containing data to be transmitted with the URL request.

This property is used in conjunction with the method property. When the value of method is GET, the value of data is appended to the value of URLRequest.url, using HTTP query-string syntax. When the method value is POST(or any value other than GET), the value of data is transmitted in the body of the HTTP request.

The URLRequest API offers binary POST support and support for URL-encoded variables, as well as support for strings. The data object can be a ByteArray, URLVariables, or String object.

The way in which the data is used depends on the type of object used:

  • If the object is a ByteArray object, the binary data of the ByteArray object is used as POST data. For GET, data of ByteArray type is not supported. Also, data of ByteArray type is not supported for FileReference.upload() and
  • If the object is a URLVariables object and the method is POST, the variables are encoded using x-www-form-urlencoded format and the resulting string is used as POST data. An exception is a call to FileReference.upload(), in which the variables are sent as separate fields in a multipart/form-data post.
  • If the object is a URLVariables object and the method is GET, the URLVariables object defines variables to be sent with the URLRequest object.
  • Otherwise, the object is converted to a string, and the string is used as the POST or GET data.

This data is not sent until a method, such as navigateToURL() or FileReference.upload(), uses the URLRequest object.

Note: The value of contentType must correspond to the type of data in the data property. See the note in the description of the contentType property.


A string that uniquely identifies the signed Adobe platform component to be stored to (or retrieved from) the Flash Player cache. An Adobe platform component is a signed file (a SWZ file) that contains SWF content that is cached persistently on a user's machine. All SWZ files are signed by Adobe. A digest corresponds to a single cached file; if you change the file in any way, its digest will change in an unpredictable way. By using a digest, you can verify the cached file across multiple domains. Two files with the same digest are the same file, and two files with different digests are not the same file. A file cannot (practically) be created to "spoof" a digest and pretend to be another digest. The digest is based on an SHA-256 message digest algorithm (64 characters long in hexadecimal format).

For example, the Flex SDK includes a SWZ for the Flex framework (and it provides the digest string for that SWZ file). You can post this SWZ on your web server and load it in your SWF file (using the load() method of a URLLoader object). If the end user's machine already has the matching SWZ file cached, the application uses the cached SWZ file. (A SWZ file matches if its digest matches the one you provide.) Otherwise, the application downloads the SWZ file from the URL you specify.

Only set the digest parameter in a URLRequest object used in a call to the URLLoader.load() method to load a SWZ file. If the digest property of a a URLRequest object is set when it is used in other methods, the application throws an IOError exception.



The digest provided does not match the digest of the file that is extracted from the downloaded signed file or the signed file loaded out of the cache. The application also throws this error if the provided digest is the wrong length or contains invalid (nonhexadecimal) characters.


Controls the HTTP form submission method.

For SWF content running in Flash Player(in the browser), this property is limited to GET or POST operations, and valid values are URLRequestMethod.GET or URLRequestMethod.POST.

For content running in Adobe AIR, you can use any string value if the content is in the application security sandbox. Otherwise, as with content running in Flash Player, you are restricted to using GET or POST operations.

For content running in Adobe AIR, when using the navigateToURL() function, the runtime treats a URLRequest that uses the POST method(one that has its method property set to URLRequestMethod.POST) as using the GET method.

Note: If running in Flash Player and the referenced form has no body, Flash Player automatically uses a GET operation, even if the method is set to URLRequestMethod.POST. For this reason, it is recommended to always include a "dummy" body to ensure that the correct method is used.



If the value parameter is not URLRequestMethod.GET or URLRequestMethod.POST.


The array of HTTP request headers to be appended to the HTTP request. The array is composed of URLRequestHeader objects. Each object in the array must be a URLRequestHeader object that contains a name string and a value string, as follows:

Flash Player and the AIR runtime impose certain restrictions on request headers; for more information, see the URLRequestHeader class description.

Not all methods that accept URLRequest parameters support the requestHeaders property, consult the documentation for the method you are calling. For example, the FileReference.upload() and methods do not support the URLRequest.requestHeaders property.

Due to browser limitations, custom HTTP request headers are only supported for POST requests, not for GET requests.


The URL to be requested.

Be sure to encode any characters that are either described as unsafe in the Uniform Resource Locator specification(see or that are reserved in the URL scheme of the URLRequest object(when not used for their reserved purpose). For example, use "%25" for the percent(%) symbol and "%23" for the number sign(#), as in "".

By default, the URL must be in the same domain as the calling file, unless the content is running in the Adobe AIR application security sandbox. If you need to load data from a different domain, put a URL policy file on the server that is hosting the data. For more information, see the description of the URLRequest class.

For content running in Adobe AIR, files in the application security sandbox - files installed with the AIR application - can access URLs using any of the following URL schemes:

  • http and https
  • file
  • app-storage
  • app

Note: IPv6(Internet Protocol version 6) is supported in AIR and in Flash Player and later. IPv6 is a version of Internet Protocol that supports 128-bit addresses(an improvement on the earlier IPv4 protocol that supports 32-bit addresses). You might need to activate IPv6 on your networking interfaces. For more information, see the Help for the operating system hosting the data. If IPv6 is supported on the hosting system, you can specify numeric IPv6 literal addresses in URLs enclosed in brackets([]), as in the following. rtmp://[2001:db8:ccc3:ffff:0:444d:555e:666f]:1935/test