.CLS File Extension

File Type:
Program Class File

Having trouble opening .cls extension? Don't panic! This page explains what cls files are as well as suggests programs you may use to open cls files. You can download these programs through this page.

What is a CLS file?

Cls file extension has Program Class file type, which is associated with the "developer files" category.

Class file is used for storing “objects” that are referenced by the source code of a single, or multiple programs in a software programming project. The file may also include definitions of variables, functions, or other data.

When developing a program, CLS files may be either saved as individual files, or included within Visual Basic Project (.VBP) files. 

To learn how you can open the given file, read the information below.

cls file icon
File Type:
Program Class File
Developer Files

How to open CLS file?

Double click the cls file to open it. The file will open automatically if file associations have been correctly installed and there is a proper program on your computer; if not, file associations may be corrupted and your OS either cannot find the proper program, or you might not have one for opening the file. First, we recommend downloading our utility to fix file association errors; then, you can download any program for opening the .cls extension from the ones suggested below. If you are certain there is nothing wrong with the file associations, you may proceed to method 2 right away; besides, if you can't make up your mind when choosing the right program, use Universal File Viewer from the last method.

Method 1: Fix file association errors

Follow these steps in order to automatically fix the cls extension associations' problem in no time:

  • Step 1: Click on "Download Solution" to download automatic tool provided by WikiExt.
  • Step 2: Click "Start Scan" to identify all potential issues.
  • Step 3: Review scan results and click "Fix Items".

File Size: 3.04 MB, Download time: < 1 min. on DSL/ADSL/Cable

This Tool is Compatible With: Windows XP, Vista, 7, 8/8.1, 10

Method 2: Download the appropriate software

The given list provides programs which may be used for opening or converting the cls file. Choose the proper program for your OS, and click it to start the download or proceed to the developer's website.

Programs that open CLS files

Method 3: Use universal file viewer

In addition to the list of programs above, we recommend using Universal File Viewer. This tool can open over 250 file extensions and, most likely, it will be able to open the cls file as well. Download Universal File Viewer for your OS.

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