IDX File Extension

Have a problem opening a .IDX file? We collect information about file formats and can explain what IDX files are. Additionally we recommend software suitable for opening or converting such files.

What is the .IDX file type?

The .idx extension is most often found in VOBsub subtitle files (a .sub/.idx file pair) extracted from DVD disks with the use of freely available utilities. SUB/IDX files contain DVD subtitles in several languages in a graphic format, which is why .sub/.idx files are much larger than plaintext .srt subtitles.

An .idx subtitle file always comes together with a .sub file, as they can be used only as a pair.

SUB/IDX subtitles can be converted into text-based subtitle formats, although the conversion process is OCR-based and requires proofreading. SUB/IDX subtitles can be opened with a media player directly to be displayed along with a movie. Most of the popular media players support the SUB/IDX subtitle format.

Alternatively, the .idx extension is also quite often associated with generic index files. An .idx file is an index made by an application or the system itself for files inside a directory, a set of directories or system-wide. The purpose of such index files is to facilitate access to large file collections and databases, enable faster search on indexed drives, track changes with indexed directories etc. IDX index files are created and used by many applications and come in a variety of internal formats. Index .idx files are not meant to be directly accessed by the user ('opened'), as they are part of how an application or system functions.

Along the generic-index line, Microsoft Outlook Express (MS OE) uses .idx files to store mailbox indexes. Each IDX mailbox index file is paired with a .mbx mailbox file in the same directory. IDX mailbox indexes are used by MS OE for quicker access to mailbox contents.

Files with the .idx extension can be found in a Java cache stored on a local system. Those are temporary cache files similar to what web browsers create. Java cache .idx files are not meant to be opened and are safe to delete.

In GPS navigation, the .idx extension is found in POI (Point Of Interest) data files used by VDO Dayton portable GPS navigation devices.

Another occurrence of the .idx extension is in .idx dictionary indexes in Hunspell MyThes (My Thesaurus). Similar dictionary indexes are also used by other spell-checking utilities.

Software to open or convert IDX files

You can open IDX files with the following programs:
KMPlayer by PandoraTV
PotPlayer by Kakao Corp.
PotPlayer by Daum Corp.
Potplayer-64 Bits
Potplayer-64 Bits by Kakao Corp.

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