Acid Tests is a test page from the Web Standards Project that checks how well a web browser follows certain web standards, especially relating to the Document Object Model and JavaScript.
When successful, the latest Acid3 test displays a gradually increasing percentage counter with colored rectangles in the background. The percentage displayed is based on the number of sub-tests passed. In addition to these the browser also has to render the page exactly like the reference page as rendered in the same browser. Like the text of the Acid2 test the text of the reference rendering is not a bitmap in order to allow for certain differences in font rendering.
