In the very first browser, created by Tim Berners-Lee in 1990, web pages could be edited directly in the browser in WYSIWYG mode. The web was conceived as a read-write medium. Later browsers however, were basically read-only. Only plain text could be entered through form controls.

WYSIWYG editing in the browser returned to the mainstream with Internet Explorer 5: The new designMode property allowed a whole document to become editable by the user. At first the feature was somewhat overlooked, possible because it came among a flurry of equally underspecified, Windows-specific, proprietary extensions to IE.