In the ever changing digital landscape, development of websites that work no matter how they are accessed is an increasingly challenging task. The investment needed to test on real versions of all available devices is simply unrealistic for all but the largest development firms. When you couple these challenges with the rapid pace of browser iteration and device release schedules, it makes having tools for virtual testing a requirement in the modern development landscape.
Most modern browsers have some ability to do virtual testing. There are also many other tools available, some even for free. The article “13 Essential Tools to Check Cross-Browser Compatibility” is a great read to start exploring some of the more popular cross-browser testing tools. One of my personal favorites is BrowserStack. While there is a fee, it has a very nice interface and a long list of available devices to test on.
If you combine these tools with knowledge of user browsing trends, you can have the outline of a very powerful testing strategy that will cover the vast majority of your site traffic. When possible, it is best to use browsing trends specific to the site you are working on. Staying on top of broader trends is also a great idea. Sites like W3Counter are an excellent way to keep up with current and new patterns in browsers and operating systems.