Contains information about a web request that the browser is about to make. An instance of this object is passed into the proxy.onRequest listener.


Values of this type are objects. They contain the following properties:

string. URL of the page into which the requested resource will be loaded.
integer. Zero if the request happens in the main frame; a positive value is the ID of a subframe in which the request happens. If the document of a (sub-)frame is loaded (type is main_frame or sub_frame), frameId indicates the ID of this frame, not the ID of the outer frame. Frame IDs are unique within a tab.
boolean. Indicates if this response will be fetched from disk cache.
The server IP address that the request will be sent to. Note that it may be a literal IPv6 address.
string. Standard HTTP method: for example, "GET" or "POST".
string. URL of the resource that triggered this request. Note that this may not be the same as the URL of the page into which the requested resource will be loaded. For example, if a document triggers a load in a different window through the target attribute of a link, or a CSS document includes an image using the url() functional notation, then this will be the URL of the original document or of the CSS document, respectively.
integer. ID of the frame that contains the frame which sent the request. Set to -1 if no parent frame exists.
string. The ID of the request. Request IDs are unique within a browser session, so you can use them to relate different events associated with the same request.
webRequest.HttpHeaders. The HTTP request headers that are going to be sent out with this request. Note that this is only included if the "requestHeaders" option was passed into addListener().
integer. ID of the tab in which the request takes place. Set to -1 if the request isn't related to a tab.
number. The time when this event fired, in milliseconds since the epoch.
webRequest.ResourceType. The type of resource being requested: for example, "image", "script", "stylesheet".
string. Target of the request.

Browser compatibility

ChromeEdgeFirefoxFirefox for AndroidOpera
Basic support No No6060 No

Document Tags and Contributors

Contributors to this page: wbamberg
Last updated by: wbamberg,