Cross-Browser Support/Compatibility does not mean creating a pixel-perfect replication of the ideal version of a website or web application, it has very little to do with what a website looks like and more related to how it functions. When it comes to browsers, we all have our preference, some like, Google Chrome, others like Mozilla Firefox, some even like Microsoft Edge, and there are several more out there. Having a website or web application function properly can make or break the project. Cross-Browser Support/Compatibility essentially means regardless of which browser is being used the functionality of the website or web application should be as identical as possible. This means the developers must test the websites or web applications on different browsers and catch different errors. One of the biggest issues is with CSS and HTML codes. These two factors are not displayed in the same manner on every browser due to lack of code support by the browser. What we mean by this is sometimes it takes a long time for a browser to adopt new CSS code or other code as native support. A good example of this is with Apple Safari and the HTML datalist tag, where this tag works on several other browsers but does not work on Safari because support has not been added by Apple's browser development team. This is just one example of several different ones which are not only on Safari but other browsers as well.
Technically speaking, yes, it makes development much harder mainly because usually there tend to be errors most people do not even think about till they run into it. To explain, most developers either use Google Chrome or Mozilla Firefox for development and those browsers tend to have most of the updated code support for HTML and CSS, however after developing a website or web application and running it on a less common web browser such as Microsoft’s Internet Explorer you will see that several things are breaking and not working properly. In order to fix this, the developer must add additional supporting code to either prevent the error and in some cases completely remove the aspect and approach the same task in another manner. This means not only does it take several days to troubleshoot errors and find solutions, but sometimes certain features must be removed entirely to present a pleasant user experience.
The simple answer is, there is not a single browser that is a one size fits all solution. However, if you are a developer there are several tools that you can use to analyze your website or web application to determine what browser is used most commonly on your targeted audience. To explain, a tool we use is Google Analytics, Google Analytics can provide quite a bit of information regarding not only user information but how they are visiting, what time of day, from where, type of device, ISP, and even the browser. We would recommend using this information to fine-tune the most popular browser and built on from there. If you are not a developer, then we recommend using Google Chrome mainly because most of the newer technological support is added into this browser almost instantaneously. This is one of the reasons Microsoft has been working on rebuilding their version of Microsoft Edge (Their new windows browser) based on Google Chrome’s Source code for additional support and to make life easier for developers. If we had to pick a second browser we would definitely say Mozilla Firefox, mainly because they have been around for so long and have a pretty large support community most issues are resolved quickly.