.XLSM File Extension
File TypeMicrosoft Excel Macro-Enabled Spreadsheet
What is an XLSM file?
An XLSM file is a macro-enabled spreadsheet created by Microsoft Excel, a widely-used spreadsheet program included in the Microsoft Office suite. It contains worksheets of cells arranged by rows and columns as well as embedded macros programmed in the Visual Basic for Applications (VBA) language. XLSM files are saved in the Open XML format introduced in Microsoft Office 2007.
XLSM files are .XLSX files with macros enabled. A macro is a useful feature that functions like a script, which allows users to automate repetitive tasks. Excel comes loaded with hundreds of macros but you can also record your own macros, which consist of keystrokes and mouse clicks that execute a specific action, and edit them to make minor changes. Some examples of macro functionality include formatting data in a selected column of a spreadsheet or applying specific mathematical equations to data.
If a user who has utilized macros to create an Excel spreadsheet wants to retain those macros when they re-open or share the document, they must save the document as an XLSM file. XLSM files are saved using the same Open XML-based format used by XLSX files, but XLSM files can store macros, while XLSX files cannot. When you open an unfamiliar XLSM file in Microsoft Excel, the program will typically ask whether you want to enable macros.
How do I open an XLSM file?
You can open XLSM files in Microsoft Excel (Windows). Excel 2007 and later versions can open XLSM files by default, and earlier versions can open XLSM files if you have installed the Microsoft Office Compatibility Pack. For security reasons, Excel does not enable XLSM files' macros by default. To enable macros in an XLSM file, click when prompted.
While XLSM files are typically legitimate Microsoft Excel spreadsheets, they may also be used to distribute and execute malware attacks on victims' computers. To protect against malicious XLSM attacks, never open or enable macros within an XLSM file unless you can verify its legitimacy and source.