CHM file format description

Many people often share .chm files without providing instructions on how to use them. This can make it difficult for users to determine which program is compatible for editing, converting, or printing .chm files. To address this issue, we have created this page to offer assistance and guidance on handling .chm files. We provide information on compatible software, editing instructions and conversion options to help users effectively interact with .chm files.

Our aim is to simplify the process and promote seamless use of the .chm file format.

4 filename extension(s) found in our database.

.chm - Compiled HTML Help

The CHM document files are related to HTML Help Workshop. The CHM file is a Compiled HTML Help. HTML Help is the standard help system for the Windows platform. The HTML Help compiler (part of the HTML Help Workshop) makes it possible to compress HTML, graphic, and other files into a relatively small compiled help (.chm) file.

Application:HTML Help Workshop
Category:Document files
Magic:- / -

Compiled HTML Help related extensions:

  • ocr FAXGrapper Fax Text
  • hjt Treepad v6 Database
  • wd2 Word Express v2 Document
  • blurb BookWright Document
  • neu Pro/ENGINEER Neutral Assembly
  • odf OpenDocument Formula

.chm - ChemDraw Chemical Structure

The CHM data files are related to ChemOffice. The CHM file is a ChemDraw Chemical Structure. ChemDraw is a major molecule editor developed by the cheminformatics company CambridgeSoft. ChemDraw is part of the ChemOffice suite of programs and is available for Macintosh and Microsoft Windows.

Category:Data files
Magic:- / -

ChemDraw Chemical Structure related extensions:

  • cds ChemDraw Stationery Document
  • cdx ChemDraw Exchange Document
  • cdxml ChemDraw XML Document
  • d ChemDraw Chemical Modeller Output

.chm - SWAT Soil Chemical Input Data

The CHM data files are related to SWAT. The CHM file is a SWAT Soil Chemical Input Data. SWAT (Soil Water Assessment Tool) is an hydrology model with the following components: Weather, surface runoff, return flow, percolation, evapotranspiration, transmission losses, pond and reservoir storage, crop growth and irrigation, groundwater flow, reach routing, nutrient and pesticide loading, water transfer.

Category:Data files
Magic:- / -

SWAT Soil Chemical Input Data related extensions:

  • bsb SWAT Sub-basin Output Data
  • bsn SWAT Basin Input Data
  • cal SWAT Auto-calibration Data
  • cio SWAT Master Watershed Data
  • cod SWAT Input Control Data
  • cst SWAT Weather Forecast Input Data

.chm - Two Worlds 2 Animation Data

The CHM game data files are related to Two Worlds 2. The CHM file is a Two Worlds 2 Animation Data. Two Worlds 2 is an action role-playing game developed by Polish video game developer Reality Pump.

Application:Two Worlds 2
Category:Game Data files
Magic:- / -

Two Worlds 2 Animation Data related extensions:

  • ddv Oddworld: Abes Oddysee Data
  • eqg EverQuest Game Data
  • vfs0 Metro 2033 Audio Data
  • lp Star Wars: The Force Unleashed Levels Data
  • c4l Clonk Game Data
  • hog Descent Mission File

Be careful.

It is important to understand that the .chm file extension is not limited to a particular set of applications. Other programs besides the intended ones can also use the .chm extension to create files. This includes potentially harmful programs or malware that may generate .chm files for various purposes. Be especially cautious with .chm files coming from untrusted or unknown sources.

Can't open a .chm 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 an extension, you receive the following message:

Select an app to open this .chm file

To set the .chm file association in Windows 11, you can follow these steps

  1. Open the Settings app by clicking on the Start menu and selecting the gear icon.
  2. In the Settings app, click on System and then select Apps from the left-hand side menu.
  3. Scroll down and click on the Default apps option.
  4. Under the Default apps section, you will find various categories such as Email, Web browser, and Music player.
  5. Locate the category that matches the file type you want to associate, such as Photos for image files or Video player for video files.
  6. Click on the current default app listed under the category. A list of available apps will appear.
  7. Choose the app you want to set as the default for that file type. If the desired app is not listed, click on More apps to see additional options or click on Look for an app in the Microsoft Store to search for apps in the Store.
  8. After selecting the app, it will become the default choice for opening files of that type.

It's worth mentioning that you don't always need to set .chm file association. Many applications can open .chm files without requiring any specific file association to be set.

The .chm file extension is often given incorrectly

Based on searches conducted on our site in the past year, we have compiled a list of the most common misspellings. These frequent misspellings can cause confusion and hinder search accuracy. Our goal in providing this list is to help users find the right information more easily and enhance their overall search experience on our website.

These misspellings were the most common in the past year:

cbm, cgm, ch, chh, chj, chk, chl, chn, cm, cmh, cmm, cnm, ctm, cym, dhm

Is it possible that the filename extension is misspelled?

There is a possibility that the .chm filename extension is misspelled. To assist users in identifying potential errors, we provide a list of similar file extensions in our database.

Filename extensions similar to .chm:

Operating systems

At, we strive to provide a seamless user experience by ensuring compatibility with a wide range of operating systems. The following is a comprehensive list of the operating systems currently supported by

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

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