Understanding Excel File Extensions: .xlsx, .xls, .xlsm

Excel file extensions explained: Whether you are using the latest version of Excel or an older version, understanding the file extensions is crucial for file management and troubleshooting. This guide will help you understand the significance and uses of .xlsx, .xls, and .xlsm file extensions.

The .xlsx File Extension (Excel 2007 and Later)

In Excel 2007 and later versions, the default file extension for an Excel workbook is .xlsx. This file format is based on the Office Open XML standard and is designed to be more efficient and secure. It supports advanced features such as formula editing, macros, and better file handling capabilities.

.xlst: Excel Template File

A special variant of the .xlsx extension is the .xlst file, which is used for Excel template files. These templates include predefined formatting and are meant to be reused regularly. When users open an .xlst file, Excel recognizes it as a template and uses it to create a new workbook.

.xlsm: Excel Macro Workbook

For users who need to automate their work processes, the .xlsm file extension is essential. This format allows the inclusion of macros, which are sequences of actions that can be executed with a single click. Examples of what can be automated with .xlsm files include inserting headings, running calculations, and more. It is important to note that .xlsm files must be trusted before enabling macros due to potential security risks.

Static File Extensions: .xls

For those working with .xls files, you likely have an older version of Excel. The .xls extension is used for workbooks created in Excel versions from 1997 to 2003. This format is less secure and less capable than the .xlsx format but is still widely used for its compatibility and familiar interface.

How to Show File Extensions

It is sometimes necessary to see file extensions to manage files effectively. Here’s how you can do it on a Windows system:

Go to Start Settings Update Security For developers Developer mode to enable developer settings if they are not enabled already. Open File Explorer. Click View in the top menu. Uncheck Show file extensions for known file types. Save your changes.

Alternatively, you can navigate to Folder Options:

Right-click on the Computer icon. Choose Properties. Navigate to the View tab under Advanced settings. The Hide extensions for known file types checkbox, when unchecked, will allow you to see file extensions. When this option is checked, file extensions are hidden.

By understanding and managing these file types, you can enhance your Excel workflow and ensure that your files are both secure and functional.