Foxit PDF IFilter is a robust implementation of Microsoft®'s IFilter indexing interface. It works with all search and retrieval products supporting the IFilter interface (for example, SharePoint® and SQL Server®). Such products use format-specific filter programs (called IFilters) for particular file formats (for example, HTML). Foxit PDF IFilter is such a program, aimed at PDF documents. The user interface for searching the documents may be Windows Explorer, a web browser, database frontend, query script, or a custom application.

Foxit PDF IFilter acts as a plug-in for full-text search engines. A search engine usually works in two steps:
?The search engine goes through a designated place (a file folder or a database), indexes all documents or newly modified documents (including PDF documents), and then stores indexing results in an internal database.
?Users specify keywords they would like to search, the search engine looks up the indexing results in the internal database, and then responding to users with all the documents that contain the specified keywords.

During step 1, the search engine itself doesn't understand the format of a PDF document. Therefore, it looks in the Windows registry for an appropriate PDF IFilter and finds the Foxit PDF IFilter. Since the PDF IFilter understands PDF format, it filters out embedded formatting, extracts text from the documents, and then returns the text back to the search engine.

Foxit PDF IFilter functions in the following search engine environments:
?Microsoft SharePoint Server: SharePoint Server 2007, SharePoint Server 2010, SharePoint Server 2013
?Microsoft Exchange Server: Exchange Server 2007, Exchange Server 2010
?Microsoft SQL Server: SQL Server 2008, SQL Server 2010, SQL Server 2014