A facility for specifying and previewing changes to a web site is described. Sets of changes to a web site are scheduled for release at a specified time. While the changes are being specified using a tool/interface, methods for showing the change as it will appear on the live web site are implemented. Inconsistencies between specified changes and changes in future releases may be identified as the changes are specified. Web page preview functionality is provided to allow any release to be viewed before publication to a live web site. The preview further allows inconsistencies between selected changes and changes in other future releases to be identified.