If you start to calculate total number of possible browser, browser version and OS combinations, the number would be in excess of 2000.
Its quite obvious one cannot test a website upon each and every single one of them. Also your target audience is not coming equally from each and every browsers. So your job as a test is to aim for highest test coverage. You should prioritize browsers that your audience is using most frequently.
In case you don’t have the traffic stats then you can make an educated guess based on browser usage statistics available on various online sources.
Now to figure out the set of web browser you need to test upon there are 2 ways based upon the type of traffic:
1.With Inbound Traffic: if you have an inbound traffic of user then you may check it from your google analytics about usage of different web browser. Google Analytics helps track your user activity and lets you know about your website’s traffic. Google Analytics give you complete insights on user behavior including the browsers and OS they have used to access your app. Using this statistics you can easily set your priority for browser testing. The more you get traffic from a specific browser or OS, the more you are going to prioritize testing of your website on that configuration.
Based upon the stats you may get to know about the web browser most preferred by the target audience. For example, Chrome at the apex of the priority list should be tested first.
2.Without Inbound Traffic: People in different locations have different liking for browsers, operating systems and devices.
So, if you’re checking for Germany location, you might want to prioritize your browsers as: Chrome, Firefox, and Safari and if you are testing for Japan you’ll need to go for Chrome, Safari, IE. That’s the catch here. Cross browser testing from different geo locations.
Once, you get to know the web browsers you have test your website upon, it will be much easier for you to test instead of checking the browser compatibility for each and every browser across the world. And to test cross-browser compatibility you can use certain testing platforms which can test your website across different set of web browser. For eg. Free Cross Browser Testing Tool on Cloud - LambdaTest (Free Cross Browser Testing Tool on Cloud - LambdaTest).