ATOMCAT file format description

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

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

1 filename extension(s) found in our database.

.atomcat - Atom Syndication Category Document

The ATOMCAT data files are related to Internet Explorer. The ATOMCAT file is an Atom Syndication Category Document. Atom is an XML-based document format that describes lists of related information known as "feeds". Feeds are composed of a number of items, known as "entries", each with an extensible set of attached metadata. For example, each entry has a title.

Application:Internet Explorer
Category:Data files
Magic:- / -

Atom Syndication Category Document related extensions:

  • oly AFP Overlay Resource
  • sbp OpenSBP CNC Program
  • bcml Biological Connection Markup Language Document
  • style SketchUp Style Data
  • iqf Integra 3.0 Query Data
  • sqd Sysquake SQ Data

Be careful.

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

Can't open a .atomcat 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 .atomcat file

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

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 .atomcat page useful, please feel free to link to this page. >> ATOMCAT file