What is .idx file extension?
The files with the .IDX extension store an index of files used by various programs. It is used by search functions to speed up searches. Once the hard disk, directory of files, or database is indexed, the data can be searched and sorted more efficiently. It is mostly used by Microsoft FoxPro, Corel QuickFinder, ESRI ArcView, ICQ, and other programs.
You can see a list of software programs here on www.easyfileopener.org that can open this file type so that you don’t need to search for it on the web. You can then open your file with this extension using a software listed below.