As an alternative to building an in-house Selenium Grid, there are various third-party service providers that host the virtual machines for companies to use in testing browser and mobile applications. There are advantages and disadvantages to using a third-party provider, and these will be discussed later on in the chapter.

One of the best-in-class providers is Sauce Labs. They provide a Selenium/Appium testing solution in the cloud, where virtual machines are created on-demand with a variety of platforms and browser or mobile devices of choice. The company boasts of having over 900 platforms for browser compatibility testing and hundreds of platforms for mobile simulator/emulator, mobile web, native, hybrid, and real-device application testing. Let's take a look at some of the key features of their service.