How to open incognito/private window with Selenium WD for different browser types?

Question

I want to test my test cases in private window or incognito window.

How to do the same in various browsers:

• firefox (prefered)
• chrome (prefered)
• IE
• safari
• opera

How to achieve it?

Answer 1

• Chrome:

  DesiredCapabilities capabilities = DesiredCapabilities.chrome();
  ChromeOptions options = new ChromeOptions();
  options.addArguments("incognito");
  capabilities.setCapability(ChromeOptions.CAPABILITY, options);
  

• FireFox:

  FirefoxProfile firefoxProfile = new FirefoxProfile();    
  firefoxProfile.setPreference("browser.privatebrowsing.autostart", true);
  

• Internet Explorer:

  DesiredCapabilities capabilities = DesiredCapabilities.internetExplorer();
  capabilities.setCapability(InternetExplorerDriver.FORCE_CREATE_PROCESS, true); 
  capabilities.setCapability(InternetExplorerDriver.IE_SWITCHES, "-private");
  

• Opera:

  DesiredCapabilities capabilities = DesiredCapabilities.operaBlink();
  OperaOptions options = new OperaOptions();
  options.addArguments("private");
  capabilities.setCapability(OperaOptions.CAPABILITY, options);
  

Answer 2

In chrome you can try using -incognito command line switch in options, not sure if there will be a problem with automation extension but worth a try.

ChromeOptions options = new ChromeOptions();
options.addArguments("incognito");

For FireFox, a special flag in the profile can be used for the purpose

FirefoxProfile firefoxProfile = new FirefoxProfile();    
firefoxProfile.setPreference("browser.private.browsing.autostart",true);

For IE

setCapability(InternetExplorerDriver.IE_SWITCHES, "-private");