CH_ file format description

Many people share .ch_ files without attaching instructions on how to use it. Yet it isn’t evident for everyone which program a .ch_ file can be edited, converted or printed with. On this page, we try to provide assistance for handling .ch_ files.

1 filename extension(s) found in our database.

.ch_ - Compressed CHM File

The CH_ data files are related to Expand. The CH_ file is a Compressed CHM File. Some files in the software distribution are provided in compressed form. These files are indicated with an underscore character as the last character in their file type. The Expand seems to be no longer supported.

Data files
- / -
Compressed CHM File related extensions:
Compressed Microsoft BMP Image
Microsoft Cabinet File
Compressed Microsoft Cabinet File
Compressed Windows Help Content
Compressed COM File
Compressed CPL File

Naturally, other applications may also use the .ch_ file extension. Even harmful programs can create .ch_ files. Be especially cautious with .ch_ files coming from an unknown source!

Can't open a .ch_ file?

When you double-click a file to open it, Windows examines the filename extension. If Windows recognizes the filename extension, it opens the file in the program that is associated with that filename extension. When Windows does not recognize a filename extension, you receive the following message:

Windows can't open this file:


To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select one from a list of programs that are installed on your computer.

To avoid this error, you need to set the file association correctly.

The .ch_ file extension is often given incorrectly!

According to the searches on our site, these misspellings were the most common in the past year:

ch, cn_

Is it possible that the filename extension is misspelled?

Similar file extensions in our database:

eSignal CH Data
Compressed Windows Help Content
Scitex Continuous Tone
CA-Clipper Clipper Header

Operating systems currently supports the following operating systems:

Windows XP/Vista, Windows 7/8/10, Windows 11, CentOS, Debian GNU/Linux, Ubuntu Linux, FreeBSD, macOS, Mac OS X, iOS, Android

If you find the information on this page useful, please feel free to link to this page.

If you have useful information about the .ch_ file format, then write to us! >> CH_ file