Secure sharing of a document on a co-browse session is implemented by causing a JavaScript implemented document viewer to create HTML5 description of a rendered view of a document's content, and transmitting the HTML5 description of the rendered view of the document content as a DOM elements on the co-browse session. The rendered view of the document is overlayed on the web page being co-browsed, which enables the participants to the co-browse session to collaboratively view the rendered view of the document. However, since the document itself only resides in the visitor's browser, the document itself is not transmitted on the co-browse session. Media URLs can also be shared, and the participants' views of the audio/video media is synchronized by causing the video to play locally at each participant but synchronized with the visitor. Live video of the participants to the co-browse session is also implemented.