chrome.devtools.network

Description

Use the chrome.devtools.network API to retrieve the information about network requests displayed by the Developer Tools in the Network panel.

Network requests information is represented in the HTTP Archive format (HAR). The description of HAR is outside of scope of this document, refer to HAR v1.2 Specification.

In terms of HAR, the chrome.devtools.network.getHAR() method returns entire HAR log, while chrome.devtools.network.onRequestFinished event provides HAR entry as an argument to the event callback.

Note that request content is not provided as part of HAR for efficiency reasons. You may call request's getContent() method to retrieve content.

If the Developer Tools window is opened after the page is loaded, some requests may be missing in the array of entries returned by getHAR(). Reload the page to get all requests. In general, the list of requests returned by getHAR() should match that displayed in the Network panel.

See DevTools APIs summary for general introduction to using Developer Tools APIs.

Manifest

The following keys must be declared in the manifest to use this API.

"devtools_page"

Examples

The following code logs URLs of all images larger than 40KB as they are loaded:

chrome.devtools.network.onRequestFinished.addListener(
  function(request) {
    if (request.response.bodySize > 40*1024) {
      chrome.devtools.inspectedWindow.eval(
          'console.log("Large image: " + unescape("' +
          escape(request.request.url) + '"))');
    }
  }
);

To try this API, install the devtools API examples from the chrome-extension-samples repository.

Types

Request

Represents a network request for a document resource (script, image and so on). See HAR Specification for reference.

Properties

getContent

void

Returns content of the response body.

The getContent function looks like:
```
(callback: function) => {...}
```
- callback
  
  function
  
  The callback parameter looks like:
```
(content: string, encoding: string) => void
```
  - content
    
    string
    
    Content of the response body (potentially encoded).
  - encoding
    
    string
    
    Empty if content is not encoded, encoding name otherwise. Currently, only base64 is supported.

Methods

getHAR()

chrome.devtools.network.getHAR(
  callback: function,
)

Returns HAR log that contains all known network requests.

Parameters

callback

function

The callback parameter looks like:
```
(harLog: object) => void
```
- harLog
  
  object
  
  A HAR log. See HAR specification for details.

Events

onNavigated

chrome.devtools.network.onNavigated.addListener(
  callback: function,
)

Fired when the inspected window navigates to a new page.

Parameters

callback

function

The callback parameter looks like:
```
(url: string) => void
```
- url
  
  string

onRequestFinished

chrome.devtools.network.onRequestFinished.addListener(
  callback: function,
)

Fired when a network request is finished and all request data are available.

Parameters

callback

function

The callback parameter looks like:
```
(request: Request) => void
```
- request
  
  Request