CLS file format description

Many people often share .cls 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 .cls files. To address this issue, we have created this page to offer assistance and guidance on handling .cls files. We provide information on compatible software, editing instructions and conversion options to help users effectively interact with .cls files.

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

6 filename extension(s) found in our database.

.cls - CLASS Group Abbreviation

The CLS isn't a filename extension, it is the abbreviated name of release group. (CLASS)

Category:Abbreviation files
Magic:- / -

CLASS Group Abbreviation related extensions:

  • flt FAiRLiGHT Group Abbreviation
  • dgr Dagger Group Abbreviation
  • dev DEViANCE Group Abbreviation
  • ep2 Nvidia EPP2.0 Profile
  • rb1 Reunion for Windows Backup File
  • rld RELOADED Group Abbreviation

.cls - Visual Basic Class Module

The CLS development files are related to Visual Basic. The CLS file is a Visual Basic Class Module. Dynamic data structures generally consist of at least some simple data storage (in our case, it will be a class module), along with a linkage to the next element in the structure.

Application:Visual Basic
Category:Development files
Magic:- / -

Visual Basic Class Module related extensions:

  • img Psion OPL Image
  • pgh PostgreSQL ECPG C Header File
  • pkh Oracle Package Header
  • csdl Conceptual Schema Definition Language Data
  • reb REBOL Source Code
  • vsdisco Visual Studio .NET Dynamic Discovery Data

.cls - ArcInfo Geocoding Classification Data

The CLS gis files are related to ESRI ArcInfo. The CLS file is an ArcInfo Geocoding Classification Data. ArcInfo is a complete and extensible geographic information system.

Application:ESRI ArcInfo
Category:GIS files
Magic:- / -

ArcInfo Geocoding Classification Data related extensions:

  • pkinfo ArcGIS Package Information Data
  • gsi GPS Tuner Map Slices Calibration Data
  • aet Chart Navigator Pro Map Data
  • pkg HERE Maps for Android Package
  • sddraft ArcGIS Service Definition Draft Data
  • sa6 DeLorme Street Atlas 6 Map Data

.cls - LaTeX Document Class Data

The CLS data files are related to teTeX. The CLS file is a LaTeX Document Class Data. LaTeX is a high-quality typesetting system, with features designed for the production of technical and scientific documentation. LaTeX is the de facto standard for the communication and publication of scientific documents.

Category:Data files
Magic:- / -

LaTeX Document Class Data related extensions:

  • aux LaTeX Auxiliary Data
  • bbl BibTeX Bibliographic Reference
  • bib BibTeX Document
  • bst BibTeX Document Style
  • dfu LaTeX Font Encoding Data
  • etx TeX Font

.cls - AOL Instant Messenger Class Data

The CLS data files are related to AOL Instant Messenger. The CLS file is an AOL Instant Messenger Class Data. AOL Instant Messenger (AIM) is an advertisement-supported proprietary instant messaging and presence computer program which uses the OSCAR instant messaging protocol and the TOC protocol to allow registered users to communicate in real time.

Application:AOL Instant Messenger
Category:Data files
Magic:- / -

AOL Instant Messenger Class Data related extensions:

  • o8s OCTGN Set Data
  • gsx Gens Saved State
  • wms WAsP Meteorological Station Data
  • ivd Beyond 20/20 Microdata Dimension Data
  • cnx IBM Rational XDE Component Instance File
  • nrl iManage Data

.class - Java Class Data

The CLASS application files are related to Java Runtime Environment. The CLASS file is a Java Class Data. CLASS file contains bytecodes for the Java Virtual Machine. Java is a class-based, object-oriented programming language that is designed to have as few implementation dependencies as possible.

Application:Java Runtime Environment
Category:Application files
Magic:- / -
Aliases:cla, clas, cls

Java Class Data related extensions:

  • cmd Windows Command File
  • qvf QlikView Sense App
  • ary SmartStart Array Configuration Script
  • u3p U3 Package
  • bas Visual Basic Module
  • com Windows Command File

Be careful.

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

Can't open a .cls 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 .cls file

To set the .cls 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 .cls file association. Many applications can open .cls files without requiring any specific file association to be set.

The .cls 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:

c1s, cis, cks, cl, cl5, clc, cle, clw, clx, clz, cms, cos, cps, cs, csl

Is it possible that the filename extension is misspelled?

There is a possibility that the .cls 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 .cls:

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