Microsoft Excel 3 for Mac Macro file
File type: Source code and script file
A .xlm3 file is a macro file created by Microsoft Excel 3 for Mac.
It contains macro instructions for automating tasks in that early Macintosh version of Excel.
File type category:
Source code and script file
Date updated: September 27, 2026
.xlm3 files belong to Microsoft Excel 3 for Mac, spreadsheet software from Microsoft used to create spreadsheets and graphs. They were used to store Excel macros, which are sequences of instructions that automate operations in a spreadsheet.
The .xlm3 extension identifies the Excel 3 for Mac version of this macro-file format. The default file extension used by Microsoft Excel for macro files is the xlm.
Excel 3 for Mac and its .xlm3 format are obsolete. The format is no longer normally used in current versions of Microsoft Excel for macOS or Windows.
Open an .xlm3 file with a compatible copy of the original Microsoft Excel 3 for Mac, if available. Current versions of Microsoft Excel may not recognize this obsolete format or may block its macros for security reasons.
If the file is important, use an isolated legacy environment and make a backup before opening it. Microsoft Excel for Windows or current Microsoft Office for Mac may not provide full support for Excel 3 for Mac macro files.
There is no usual standalone conversion for an .xlm3 macro file. If a compatible version of Excel can open it, copy or recreate the macro in a newer Excel workbook and save the result in a current Excel format.
Old macro instructions may require manual changes before they work in a modern version of Microsoft Excel.
Software applications that handle other tasks involving xlm3 files:
Microsoft Windows
Apple macOS / Mac OS X
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