An essential part of web development involves building websites that are cross-browser compatible. Cross-browser compatibility ensures a website will look and function correctly in a range of different web browsers.
Unlike a few years ago when Microsoft's Internet Explorer dominated the web browser market, the chances are users are more likely to use a wider variety of web browsers to navigate the internet, such as Apple's Safari web browser or Mozilla's Firefox, there are others too such as Opera and Google's Chrome. This is down to a number of reasons including the increase in popularity of Apple Mac computers and well publicised security problems with Internet Explorer.
Web browser testing is essential to ensure a user experience is consistent irrespective of which browser a user chooses to browse the web but also to ensure you don't alienate a potential customers.
Supporting the latest versions of each web browser isn't necessarily good enough however. Often, as is the case with Internet Explorer (IE), a website has to be compatible with a number of versions of a web browser as is currently the case with IE 6, IE 7 and IE 8. The stats below obtained from Google Analytics show Internet Explorer versions used to browse a client website.
To determine what web browsers you should support you need to analyse your log files* for browser versions your visitors are using to browse your website. If you don't have a website yet then check the latest web browser statistics for the market share of each browser version.
* If you are using Google Analytics, you can obtain browser share like the graph below by clicking on Visitors > Browser Capabilities > Browsers in the left navigation.
If you already have a website and you're wondering what it looks like on different web browsers you might want to try browser shots, a free web browser testing tool (However I would suggest that you only test web browsers you wish to support).
Remember: If you are commissioning a web developer to build a website on your behalf ensure you stipulate what web browsers you wish to support before any web development begins.