webContents is an EventEmitter .

It is responsible for rendering and controlling a web page and is a property of the BrowserWindow object. An example of accessing the webContents object:

const BrowserWindow = require('electron').BrowserWindow;
var win = new BrowserWindow({width: 800, height: 1500});
win.loadURL("http://github.com");
var webContents = win.webContents;
Events
The webContents object emits the following events:
Event: 'did-finish-load'
Emitted when the navigation is done, i.e. the spinner of the tab has stopped
spinning, and the onload event was dispatched.
Event: 'did-fail-load'
Returns:
event Event
errorCode Integer
errorDescription String
validatedURL String
This event is like did-finish-load but emitted when the load failed or was
cancelled, e.g. window.stop() is invoked.
The full list of error codes and their meaning is available here.
Event: 'did-frame-finish-load'
Returns:
event Event
isMainFrame Boolean
Emitted when a frame has done navigation.
Event: 'did-start-loading'
Corresponds to the points in time when the spinner of the tab started spinning.
Event: 'did-stop-loading'
Corresponds to the points in time when the spinner of the tab stopped spinning.
Event: 'did-get-response-details'
Returns:
event Event
status Boolean
newURL String
originalURL String
httpResponseCode Integer
requestMethod String
referrer String
headers Object
Emitted when details regarding a requested resource are available.
status indicates the socket connection to download the resource.
Event: 'did-get-redirect-request'
Returns:
event Event
oldURL String
newURL String
isMainFrame Boolean
httpResponseCode Integer
requestMethod String
referrer String
headers Object
Emitted when a redirect is received while requesting a resource.
Event: 'dom-ready'
Returns:
event Event
Emitted when the document in the given frame is loaded.
Event: 'page-favicon-updated'
Returns:
event Event
favicons Array - Array of URLs
Emitted when page receives favicon urls.
Event: 'new-window'
Returns:
event Event
url String
frameName String
disposition String - Can be default, foreground-tab, background-tab,
new-window and other.
options Object - The options which will be used for creating the new
BrowserWindow.
Emitted when the page requests to open a new window for a url. It could be
requested by window.open or an external link like <a target='_blank'>.
By default a new BrowserWindow will be created for the url.
Calling event.preventDefault() will prevent creating new windows.
Event: 'will-navigate'
Returns:
event Event
url String
Emitted when a user or the page wants to start navigation. It can happen when
the window.location object is changed or a user clicks a link in the page.
This event will not emit when the navigation is started programmatically with
APIs like webContents.loadURL and webContents.back.
It is also not emitted for in-page navigations, such as clicking anchor links
or updating the window.location.hash. Use did-navigate-in-page event for
this purpose.
Calling event.preventDefault() will prevent the navigation.
Event: 'did-navigate'
Returns:
event Event
url String
Emitted when a navigation is done.
This event is not emitted for in-page navigations, such as clicking anchor links
or updating the window.location.hash. Use did-navigate-in-page event for
this purpose.
Event: 'did-navigate-in-page'
Returns:
event Event
url String
Emitted when an in-page navigation happened.
When in-page navigation happens, the page URL changes but does not cause
navigation outside of the page. Examples of this occurring are when anchor links
are clicked or when the DOM hashchange event is triggered.
Event: 'crashed'
Emitted when the renderer process has crashed.
Event: 'plugin-crashed'
Returns:
event Event
name String
version String
Emitted when a plugin process has crashed.
Event: 'destroyed'
Emitted when webContents is destroyed.
Event: 'devtools-opened'
Emitted when DevTools is opened.
Event: 'devtools-closed'
Emitted when DevTools is closed.
Event: 'devtools-focused'
Emitted when DevTools is focused / opened.
Event: 'certificate-error'
Returns:
event Event
url URL
error String - The error code
certificate Object

data Buffer - PEM encoded data
issuerName String
callback Function
Emitted when failed to verify the certificate for url.
The usage is the same with the certificate-error event of
app.
Event: 'select-client-certificate'
Returns:
event Event
url URL
certificateList [Objects]

data Buffer - PEM encoded data
issuerName String - Issuer's Common Name
callback Function
Emitted when a client certificate is requested.
The usage is the same with the select-client-certificate event of
app.
Event: 'login'
Returns:
event Event
request Object

method String
url URL
referrer URL
authInfo Object

isProxy Boolean
scheme String
host String
port Integer
realm String
callback Function
Emitted when webContents wants to do basic auth.
The usage is the same with the login event of app.
Event: 'found-in-page'
Returns:
event Event
result Object

requestId Integer
finalUpdate Boolean - Indicates if more responses are to follow.
matches Integer (optional) - Number of Matches.
selectionArea Object (optional) - Coordinates of first match region.
Emitted when a result is available for
webContents.findInPage request.
Event: 'media-started-playing'
Emitted when media starts playing.
Event: 'media-paused'
Emitted when media is paused or done playing.
Event: 'did-change-theme-color'
Emitted when a page's theme color changes. This is usually due to encountering a meta tag:
<meta name='theme-color' content='#ff0000'>
Event: 'cursor-changed'
Returns:
event Event
type String
image NativeImage (optional)
scale Float (optional)
Emitted when the cursor's type changes. The type parameter can be default,
crosshair, pointer, text, wait, help, e-resize, n-resize,
ne-resize, nw-resize, s-resize, se-resize, sw-resize, w-resize,
ns-resize, ew-resize, nesw-resize, nwse-resize, col-resize,
row-resize, m-panning, e-panning, n-panning, ne-panning, nw-panning,
s-panning, se-panning, sw-panning, w-panning, move, vertical-text,
cell, context-menu, alias, progress, nodrop, copy, none,
not-allowed, zoom-in, zoom-out, grab, grabbing, custom.
If the type parameter is custom, the image parameter will hold the custom
cursor image in a NativeImage, and the scale will hold scaling information
for the image.
Instance Methods
The webContents object has the following instance methods:
webContents.loadURL(url[, options])
url URL
options Object (optional)

httpReferrer String - A HTTP Referrer url.
userAgent String - A user agent originating the request.
extraHeaders String - Extra headers separated by "\n"
Loads the url in the window, the url must contain the protocol prefix,
e.g. the http:// or file://. If the load should bypass http cache then
use the pragma header to achieve it.
const options = {"extraHeaders" : "pragma: no-cache\n"}
webContents.loadURL(url, options)
webContents.downloadURL(url)
url URL
Initiates a download of the resource at url without navigating. The
will-download event of session will be triggered.
webContents.getURL()
Returns URL of the current web page.
var win = new BrowserWindow({width: 800, height: 600});
win.loadURL("http://github.com");
var currentURL = win.webContents.getURL();
webContents.getTitle()
Returns the title of the current web page.
webContents.isLoading()
Returns whether web page is still loading resources.
webContents.isWaitingForResponse()
Returns whether the web page is waiting for a first-response from the main
resource of the page.
webContents.stop()
Stops any pending navigation.
webContents.reload()
Reloads the current web page.
webContents.reloadIgnoringCache()
Reloads current page and ignores cache.
webContents.canGoBack()
Returns whether the browser can go back to previous web page.
webContents.canGoForward()
Returns whether the browser can go forward to next web page.
webContents.canGoToOffset(offset)
offset Integer
Returns whether the web page can go to offset.
webContents.clearHistory()
Clears the navigation history.
webContents.goBack()
Makes the browser go back a web page.
webContents.goForward()
Makes the browser go forward a web page.
webContents.goToIndex(index)
index Integer
Navigates browser to the specified absolute web page index.
webContents.goToOffset(offset)
offset Integer
Navigates to the specified offset from the "current entry".
webContents.isCrashed()
Whether the renderer process has crashed.
webContents.setUserAgent(userAgent)
userAgent String
Overrides the user agent for this web page.
webContents.getUserAgent()
Returns a String representing the user agent for this web page.
webContents.insertCSS(css)
css String
Injects CSS into the current web page.
webContents.executeJavaScript(code[, userGesture, callback])
code String
userGesture Boolean (optional)
callback Function (optional) - Called after script has been executed.

result
Evaluates code in page.
In the browser window some HTML APIs like requestFullScreen can only be
invoked by a gesture from the user. Setting userGesture to true will remove
this limitation.
webContents.setAudioMuted(muted)
muted Boolean
Mute the audio on the current web page.
webContents.isAudioMuted()
Returns whether this page has been muted.
webContents.undo()
Executes the editing command undo in web page.
webContents.redo()
Executes the editing command redo in web page.
webContents.cut()
Executes the editing command cut in web page.
webContents.copy()
Executes the editing command copy in web page.
webContents.paste()
Executes the editing command paste in web page.
webContents.pasteAndMatchStyle()
Executes the editing command pasteAndMatchStyle in web page.
webContents.delete()
Executes the editing command delete in web page.
webContents.selectAll()
Executes the editing command selectAll in web page.
webContents.unselect()
Executes the editing command unselect in web page.
webContents.replace(text)
text String
Executes the editing command replace in web page.
webContents.replaceMisspelling(text)
text String
Executes the editing command replaceMisspelling in web page.
webContents.insertText(text)
text String
Inserts text to the focused element.
webContents.findInPage(text[, options])
text String - Content to be searched, must not be empty.
options Object (optional)

forward Boolean - Whether to search forward or backward, defaults to true.
findNext Boolean - Whether the operation is first request or a follow up,
defaults to false.
matchCase Boolean - Whether search should be case-sensitive,
defaults to false.
wordStart Boolean - Whether to look only at the start of words.
defaults to false.
medialCapitalAsWordStart Boolean - When combined with wordStart,
accepts a match in the middle of a word if the match begins with an
uppercase letter followed by a lowercase or non-letter.
Accepts several other intra-word matches, defaults to false.
Starts a request to find all matches for the text in the web page and returns an Integer
representing the request id used for the request. The result of the request can be
obtained by subscribing to found-in-page event.




    

webContents.stopFindInPage(action)
action String - Specifies the action to take place when ending
webContents.findInPage request.

clearSelection - Translate the selection into a normal selection.
keepSelection - Clear the selection.
activateSelection - Focus and click the selection node.
Stops any findInPage request for the webContents with the provided action.
webContents.on('found-in-page', function(event, result) {
  if (result.finalUpdate)
    webContents.stopFindInPage("clearSelection");
const requestId = webContents.findInPage("api");
webContents.hasServiceWorker(callback)
callback Function
Checks if any ServiceWorker is registered and returns a boolean as
response to callback.
webContents.unregisterServiceWorker(callback)
callback Function
Unregisters any ServiceWorker if present and returns a boolean as
response to callback when the JS promise is fulfilled or false
when the JS promise is rejected.
webContents.print([options])
options Object (optional)

silent Boolean - Don't ask user for print settings. Default is false.
printBackground Boolean - Also prints the background color and image of
the web page. Default is false.
Prints window's web page. When silent is set to false, Electron will pick
up system's default printer and default settings for printing.
Calling window.print() in web page is equivalent to calling
webContents.print({silent: false, printBackground: false}).
Note: On Windows, the print API relies on pdf.dll. If your application
doesn't need the print feature, you can safely remove pdf.dll to reduce binary
size.
webContents.printToPDF(options, callback)
options Object

marginsType Integer - Specifies the type of margins to use. Uses 0 for
default margin, 1 for no margin, and 2 for minimum margin.
pageSize String - Specify page size of the generated PDF. Can be A3,
A4, A5, Legal, Letter and Tabloid.
printBackground Boolean - Whether to print CSS backgrounds.
printSelectionOnly Boolean - Whether to print selection only.
landscape Boolean - true for landscape, false for portrait.
callback Function
Prints window's web page as PDF with Chromium's preview printing custom
settings.
The callback will be called with callback(error, data) on completion. The
data is a Buffer that contains the generated PDF data.
By default, an empty options will be regarded as:
  marginsType: 0,
  printBackground: false,
  printSelectionOnly: false,
  landscape: false
const BrowserWindow = require('electron').BrowserWindow;
const fs = require('fs');
var win = new BrowserWindow({width: 800, height: 600});
win.loadURL("http://github.com");
win.webContents.on("did-finish-load", function() {
  // Use default printing options
  win.webContents.printToPDF({}, function(error, data) {
    if (error) throw error;
    fs.writeFile("/tmp/print.pdf", data, function(error) {
      if (error)
        throw error;
      console.log("Write PDF successfully.");
webContents.addWorkSpace(path)
path String
Adds the specified path to DevTools workspace. Must be used after DevTools
creation:
mainWindow.webContents.on('devtools-opened', function() {
  mainWindow.webContents.addWorkSpace(__dirname);
webContents.removeWorkSpace(path)
path String
Removes the specified path from DevTools workspace.
webContents.openDevTools([options])
options Object (optional)

detach Boolean - opens DevTools in a new window
Opens the devtools.
webContents.closeDevTools()
Closes the devtools.
webContents.isDevToolsOpened()
Returns whether the devtools is opened.
webContents.isDevToolsFocused()
Returns whether the devtools view is focused .
webContents.toggleDevTools()
Toggles the developer tools.
webContents.inspectElement(x, y)
x Integer
y Integer
Starts inspecting element at position (x, y).
webContents.inspectServiceWorker()
Opens the developer tools for the service worker context.
webContents.send(channel[, arg1][, arg2][, ...])
channel String
arg (optional)
Send an asynchronous message to renderer process via channel, you can also
send arbitrary arguments. Arguments will be serialized in JSON internally and
hence no functions or prototype chain will be included.
The renderer process can handle the message by listening to channel with the
ipcRenderer module.
An example of sending messages from the main process to the renderer process:
// In the main process.
var window = null;
app.on('ready', function() {
  window = new BrowserWindow({width: 800, height: 600});
  window.loadURL('file://' + __dirname + '/index.html');
  window.webContents.on('did-finish-load', function() {
    window.webContents.send('ping', 'whoooooooh!');
<!-- index.html -->
  <script>
    require('electron').ipcRenderer.on('ping', function(event, message) {
      console.log(message);  // Prints "whoooooooh!"
  </script>
</body>
</html>
webContents.enableDeviceEmulation(parameters)
parameters Object, properties:
screenPosition String - Specify the screen type to emulate
  (default: desktop)

desktop
mobile
screenSize Object - Set the emulated screen size (screenPosition == mobile)

width Integer - Set the emulated screen width
height Integer - Set the emulated screen height
viewPosition Object - Position the view on the screen
  (screenPosition == mobile) (default: {x: 0, y: 0})

x Integer - Set the x axis offset from top left corner
y Integer - Set the y axis offset from top left corner
deviceScaleFactor Integer - Set the device scale factor (if zero defaults to
  original device scale factor) (default: 0)
viewSize Object - Set the emulated view size (empty means no override)

width Integer - Set the emulated view width
height Integer - Set the emulated view height
fitToView Boolean - Whether emulated view should be scaled down if
  necessary to fit into available space (default: false)
offset Object - Offset of the emulated view inside available space (not in
  fit to view mode) (default: {x: 0, y: 0})

x Float - Set the x axis offset from top left corner
y Float - Set the y axis offset from top left corner
scale Float - Scale of emulated view inside available space (not in fit to
  view mode) (default: 1)
Enable device emulation with the given parameters.
webContents.disableDeviceEmulation()
Disable device emulation enabled by webContents.enableDeviceEmulation.
webContents.sendInputEvent(event)
event Object

type String (required) - The type of the event, can be mouseDown,
mouseUp, mouseEnter, mouseLeave, contextMenu, mouseWheel,
mouseMove, keyDown, keyUp, char.
modifiers Array - An array of modifiers of the event, can
include shift, control, alt, meta, isKeypad, isAutoRepeat,
leftButtonDown, middleButtonDown, rightButtonDown, capsLock,
numLock, left, right.
Sends an input event to the page.
For keyboard events, the event object also have following properties:
keyCode Char or String (required) - The character that will be sent
as the keyboard event. Can be a single UTF-8 character, or the name of the
key that generates the event. Accepted key names are enter, backspace,
delete, tab, escape, control, alt, altgr (Windows only), shift,
end, home, insert, left, up, right, down, pageUp, pageDown,
printScreen, meta, cmd (OSX only), command (OSX only), option
(OSX only)
For mouse events, the event object also have following properties:
x Integer (required)
y Integer (required)
button String - The button pressed, can be left, middle, right
globalX Integer
globalY Integer
movementX Integer
movementY Integer
clickCount Integer
For the mouseWheel event, the event object also have following properties:
deltaX Integer
deltaY Integer
wheelTicksX Integer
wheelTicksY Integer
accelerationRatioX Integer
accelerationRatioY Integer
hasPreciseScrollingDeltas Boolean
canScroll Boolean
webContents.beginFrameSubscription(callback)
callback Function
Begin subscribing for presentation events and captured frames, the callback
will be called with callback(frameBuffer) when there is a presentation event.
The frameBuffer is a Buffer that contains raw pixel data. On most machines,
the pixel data is effectively stored in 32bit BGRA format, but the actual
representation depends on the endianness of the processor (most modern
processors are little-endian, on machines with big-endian processors the data
is in 32bit ARGB format).
webContents.endFrameSubscription()
End subscribing for frame presentation events.
webContents.savePage(fullPath, saveType, callback)
fullPath String - The full file path.
saveType String - Specify the save type.

HTMLOnly - Save only the HTML of the page.
HTMLComplete - Save complete-html page.
MHTML - Save complete-html page as MHTML.
callback Function - function(error) {}.

error Error
Returns true if the process of saving page has been initiated successfully.
win.loadURL('https://github.com');
win.webContents.on('did-finish-load', function() {
  win.webContents.savePage('/tmp/test.html', 'HTMLComplete', function(error) {
    if (!error)
      console.log("Save page successfully");
Instance Properties
WebContents objects also have the following properties:
webContents.session
Returns the session object used by this webContents.
webContents.hostWebContents
Returns the WebContents that might own this WebContents.
webContents.devToolsWebContents
Get the WebContents of DevTools for this WebContents.
Note: Users should never store this object because it may become null
when the DevTools has been closed.
webContents.debugger
Debugger API serves as an alternate transport for remote debugging protocol.
try {
  win.webContents.debugger.attach("1.1");
} catch(err) {
  console.log("Debugger attach failed : ", err);
win.webContents.debugger.on('detach', function(event, reason) {
  console.log("Debugger detached due to : ", reason);
win.webContents.debugger.on('message', function(event, method, params) {
  if (method == "Network.requestWillBeSent") {
    if (params.request.url == "https://www.github.com")
      win.webContents.debugger.detach();
win.webContents.debugger.sendCommand("Network.enable");
webContents.debugger.attach([protocolVersion])
protocolVersion String (optional) - Requested debugging protocol version.
Attaches the debugger to the webContents.
webContents.debugger.isAttached()
Returns a boolean indicating whether a debugger is attached to the webContents.
webContents.debugger.detach()
Detaches the debugger from the webContents.
webContents.debugger.sendCommand(method[, commandParams, callback])
method String - Method name, should be one of the methods defined by the
 remote debugging protocol.
commandParams Object (optional) - JSON object with request parameters.
callback Function (optional) - Response

error Object - Error message indicating the failure of the command.
result Object - Response defined by the 'returns' attribute of
 the command description in the remote debugging protocol.
Send given command to the debugging target.
Event: 'detach'
event Event
reason String - Reason for detaching debugger.
Emitted when debugging session is terminated. This happens either when
webContents is closed or devtools is invoked for the attached webContents.
Event: 'message'
event Event
method String - Method name.
params Object - Event parameters defined by the 'parameters'
 attribute in the remote debugging protocol.
Emitted whenever debugging target issues instrumentation event.