Adobe labs provides free tool to test websites in different browsers in one click. The professional webmasters, designers and developers can use this tool to check their websites in different browsers in one click.

BrowserLab provides web designers exact renderings of their web pages in multiple browsers and operating systems. BrowserLab is a powerful solution for cross-browser compatibility testing, featuring multiple viewing and comparison tools. BrowserLab requires registration, to obtain membership account checkout here.

Adobe Labs states that “The BrowserLab free preview is available to a limited number of users for monitoring its performance”

BrowserLab – Supported Browsers and Operating Systems

• Firefox 2.X and 3.X (Windows XP and Mac OS X)
• Internet Explorer 6.X and 7.X (Windows XP)
• Safari 3.X (Mac OS X)

BrowserLab allows to select two browsers at a time, where you can compare the difference between two browsers. The above picture demonstrates difference of the tothetech blog in IE 7 Windows XP and Safari3.0 OS X

Browser Sets allow designers to customize, edit, and save a combination of browsers to test.

If you are using Dreamweaver CS 4 you can add BrowserLab powerful functionalities such as the ability to test local content and different states of interactive pages. For detailed instructions about BrowserLabs check out here.