Deleting web browser data by maintaining a set of Uniform Resource Locators (URL) hostnames, where a URL hostname is added to the set of hostnames responsive to the URL being accessed by a web browser and responsive to determining that predefined grouping conditions that define a logical group is met by the URL, and deleting one or more types of data maintained by the web browser in association with URLs associated with the hostnames in the set of hostnames, where the deleting is performed in accordance with a predefined deletion policy that specifies the types of data that are to be deleted and predefined deletion conditions, and where the deleting is performed responsive to determining that the predefined deletion conditions are met and determining that the web browser is not currently accessing any URL associated with the hostnames in the set of hostnames.