# `window.open` Function > Open a new window and load a URL. When `window.open` is called to create a new window in a web page, a new instance of `BrowserWindow` will be created for the `url` and a proxy will be returned to `window.open` to let the page have limited control over it. The proxy has limited standard functionality implemented to be compatible with traditional web pages. For full control of the new window you should create a `BrowserWindow` directly. The newly created `BrowserWindow` will inherit the parent window's options by default. To override inherited options you can set them in the `features` string. ### `window.open(url[, frameName][, features])` * `url` String * `frameName` String (optional) * `features` String (optional) Returns `BrowserWindowProxy` - Creates a new window and returns an instance of `BrowserWindowProxy` class. The `features` string follows the format of standard browser, but each feature has to be a field of `BrowserWindow`'s options. **Note:** Node integration will always be disabled in the opened `window` if it is disabled on the parent window. ### `window.opener.postMessage(message, targetOrigin)` * `message` String * `targetOrigin` String Sends a message to the parent window with the specified origin or `*` for no origin preference. ## Class: BrowserWindowProxy > Manipulate the child browser window The `BrowserWindowProxy` object is returned from `window.open` and provides limited functionality with the child window. ### Instance Methods The `BrowserWindowProxy` object has the following instance methods: #### `win.blur()` Removes focus from the child window. #### `win.close()` Forcefully closes the child window without calling its unload event. #### `win.eval(code)` * `code` String Evaluates the code in the child window. #### `win.focus()` Focuses the child window (brings the window to front). #### `win.print()` Invokes the print dialog on the child window. #### `win.postMessage(message, targetOrigin)` * `message` String * `targetOrigin` String Sends a message to the child window with the specified origin or `*` for no origin preference. In addition to these methods, the child window implements `window.opener` object with no properties and a single method. ### Instance Properties The `BrowserWindowProxy` object has the following instance properties: #### `win.closed` A Boolean that is set to true after the child window gets closed.