What Are IDX Files?

By Mitchell White

IDX files are files that end with the file extension ".idx." This file extension is used in various contexts: it represents a movie subtitle file for many different DVD playback and subtitle editing programs, an index file for various programs, an HMI historical log index file created by InTouch software, an Outlook Express mailbox index file and a navigation POI file for a VDO Dayton GPS.

Movie Subtitle Files

.idx is a movie subtitle file of a miscellaneous file type. It displays subtitles for the DVD playback and subtitle editing programs VideoLAN VLC media player for the Mac OS, Windows and Linux operating systems; MPlayer for Mac OS; and CyberLink PowerDVD 10 Mark II, URUWorks Subtitle Workshop and DVDSubEdit for Windows.

Index Files

Additionally, .idx files are used as system file-type index files for various Windows programs used by the operating system itself. These programs include ICQ, Microsoft FoxPro, ESRI ArcView, ESRI ArcGIS Desktop and Corel QuickFinder. An index file indexes hard disks, file directories and databases to improve the speed and efficiency of search and sort functions.

HMI Historical Log Index Files

.idx is also an an HMI historical log index file of the data file type, used with InTouch Human-Machine Interface or ReportBuilder software for the Windows Wonderware InTouch and WorkSmart Automation ReportBuilder programs. This version of .idx runs reports from collected data. Since it is of the data file type, it is installed directly with certain applications.

Outlook Express Mailbox Index Files

IDX files are also Outlook Express Mailbox index files of the text file type useful with Microsoft Outlook Express for the Windows operating system. This type of .idx indexes email messages in a textual data format. These IDX files are stored inside of .mbx files or Outlook Express mailbox files.

Navigation POI Files

.idx is, additionally, a navigation POI file, also of the data file type, for a VDO Dayton GPS PND (portable navigation device). In this context, an .idx file stores navigational points of interest for the device including indexes, coordinates, names and types. Points of interest are stored together under a header and can be transferred with a USB cable.

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