Systems that support the co-authoring of web sites often allow users to freely edit pages. This can result in semantic inconsistencies within and between pages. We propose a change awareness mechanism that monitors intra- and inter-document edits, taking into account changes made to a page and pages connected to it through html or transclusion links. The effect of all the changes is computed based on various metrics and on different semantic levels according to user preferences. A visualisation tool indicates how much a document and documents linked to it have changed. An edit profile allows users to easily spot parts with ``interesting" changes within web pages.