Methods and systems are provided for testing visual elements in a rendered web page. The method includes defining a gold image at a first point within a web application, taking a screen shot of an actual image at the first point during execution of the web application, and comparing the gold image to the actual image and generating a difference image based on the comparison. The difference image may include a first region highlighting a first difference between the gold image and the actual image within an area common to both images, and a second region highlighting a second difference between the gold image and the actual image which is not within an area common to both images.