index.dat

In the Microsoft Windows operating system, index.dat is a hidden database file used by the Internet Explorer web browser. It functions as an information storage database of recent browser activity, enabling quick access to that information when needed again by Internet Explorer, thus improving browser performance.

==Function== The index.dat file is a database file. It is a repository of information such as web URLs, search queries and recently opened files. Its purpose is to enable quick access to data used by Internet Explorer. For example, every web address visited is stored in the index.dat file, allowing Internet Explorer to quickly find Autocomplete matches as the user types a web address. The index.dat file is user-specific and is open as long as a user is logged into his or her Windows user account. Separate index.dat files exist for the Internet Explorer history, cache, and cookies.