Box Acid Test

1998 October

Todd Fahrner began working on the Box Acid Test (Acid1) project, which tested if web browsers supported the CSS language. The test itself is a simple web page that contains several HTML elements modified by CSS. The browser either displays the page correctly and passes the test or it fails. Most of the browsers of the time failed the Acid1 test. In January 1999, the Box Acid Test was included in the W3C’s official CSS1 set of tests.