.CHI File

The chi file extension is related to the Microsoft Help file index files.

Index file used when you ship chm files that are likely to remain on a CD-ROM, as in the case of the MSDN Library.

The chi file allows certain navigation information to be installed locally on a hard disk for quick access, while the main content lives on the CD-ROM.

A chi file should not be used in a non-CD-ROM scenario. When a chi file is not used, all the information that would be in it remains in the chm itself.

Microsoft Compiled HTML Help is a proprietary format for online help files, developed by Microsoft and first released in 1997 as a successor to the Microsoft WinHelp format.

It was first introduced with the release of Windows 98, and is still supported and distributed through Windows XP, Vista and Windows 7 platforms.

How to open:

This file type is not meant to be opened directly, there is no software that could open and work with it directly, or there is no information available in public sources about opening this file type. This is usually the case of some internal data files, caches, temporary files etc.

How to convert:

As far as we know, this .chi file type can't be converted to any other file format. This is usually the case of system, configuration, temporary, or data files containing data exclusive to only one software and used for its own purposes. Also some proprietary or closed file formats cannot be converted to more common file types in order to protect the intellectual property of the developer, which is for example the case of some DRM-protected multimedia files.