Approaches for synchronizing cookie data across a virtualized web browser. When a user instructs a virtualized web browser, executing on a host operating system, to display a web page, a host module executing on the host operating system instructs a particular virtual machine to retrieve the web page within the particular virtual machine. The host module provides cookie data for the user to the guest module. The cookie data identifies one or more cookies deemed to be pertinent to the retrieval of the web page. The guest module provides, to the host module, screen data content for use in displaying the web page.