Customizing Firefox with FirefoxOptions – Sauce Labs

If you need to test the Firefox browser with certain browser options, you can use FirefoxOptions to customize browser settings for your tests. You can find more information about setting FirefoxOptions in the official Selenium documentation link.

Here are a few examples of what you can do with changing browser settings.

Setting Browser Language

FirefoxOptions ffOpts = new FirefoxOptions();
FirefoxProfile profile = new FirefoxProfile();

profile.setPreference("intl.accept_languages", "es");


ffOpts.setCapability(“platformName”, “Windows 10”);
ffOpts.setCapability(“browserVersion”, “latest”);
ffOpts.setProfile(profile);

Installing a Firefox Extension, such as Modify Headers

You will need to download the .xpi file to your local machine before creating the profile settings.

FirefoxOptions ffOpts = new FirefoxOptions();
FirefoxProfile profile = new FirefoxProfile();

profile.addExtension(new File("/path/to/xpi/file"));
profile.setPreference("general.useragent.override", "UA-STRING");
profile.setPreference("extensions.modify_headers.currentVersion", "0.7.1.1-signed");
profile.setPreference("modifyheaders.headers.count", 1);
profile.setPreference("modifyheaders.headers.action0", "Add");
profile.setPreference("modifyheaders.headers.name0", "X-Forwarded-For");
profile.setPreference("modifyheaders.headers.value0", "161.76.79.1");
profile.setPreference("modifyheaders.headers.enabled0", true);
profile.setPreference("modifyheaders.config.active", true);
profile.setPreference("modifyheaders.config.alwaysOn", true);
profile.setPreference("modifyheaders.config.start", true);

ffOpts.setProfile(profile);