CSS layouts may look different when viewed through different browsers so it is important that you test your layouts in different browsers.
Benefits of testing CSS layouts on different browsers
This is always important because you want to know if your CSS layout is compatible with the browser that your readers use. You also need to know which browser works better with edits that you may want to do with your page. A browser is good if it automatically updates when elements are added dynamically.
Using BrowserCam to quickly test layouts of CSS
BrowserCam is one of the most useful tools in testing websites in a variety of settings using different browsers. Although it is not free, BrowserCam is popular among developers because it allows you to test your website against different browsers and operating systems. It also allows you to take screenshots of your page as it is viewed in different browsers.
Testing tips when dealing with CSS layouts
There are many ways to test for failures in CSS layouts. Focus on real world coverage and pre-release beta testing. Do asmoke test as well as automated tests. You can look for various testing suites online.