What is an XLSM file?
An .XLSM file is a Microsoft Excel Macro-Enabled Spreadsheet. Microsoft created this format for Microsoft Excel. It stores data in rows, columns, and worksheets. The main difference between this format and standard spreadsheets is that it contains macros. Macros are automated scripts written in Visual Basic for Applications (VBA). The underlying file structure uses a ZIP archive that contains multiple XML files.
How to open XLSM files?
You can open .XLSM files with Microsoft Excel. Alternative spreadsheet software like LibreOffice Calc or Google Sheets can open the spreadsheet data, but they generally cannot run the VBA macros. Because macros can contain malicious code, you must be careful when you open an .XLSM file from an unknown source.
Best practices and troubleshooting
If you cannot open the file or if you suspect it might be a different format, viewer.online/xlsm analyzes .XLSM files to identify their exact format and creator software. It shows which programs can open the file, and usually previews it. If you need to change the file format for safety or compatibility, you can convert the .XLSM file to a standard .XLSX, .CSV, or .PDF format on convert.guru.
Summary
viewer.online/xlsm directly opens and previews .XLSM files in the browser, eliminating the need to install software or troubleshoot compatibility issues.