Software & Apps File Types What Is an XLM File? How to Open, Edit, & Convert XLM Files By Tim Fisher General Manager, VP, Lifewire.com Tim Fisher has 30+ years' professional technology support experience. He writes troubleshooting content and is the General Manager of Lifewire. our editorial process Facebook Twitter LinkedIn Tim Fisher Updated July 09, 2019 XLM Files. File Types Design Cryptocurrency MS Office Windows Linux Google Drive Apps File Types Backup & Utilities View More Tweet Share Email A file with the XLM file extension is an Excel 4.0 Macro file. Macros allow automation so that repetitive tasks can be "played" to save time and lower the likelihood of errors. Newer Excel formats like XLSM and XLTM are similar to XLM in that they can store macros, but unlike XLM files, they are actual spreadsheet files that include macros. An XLM file is an outdated format that is, in and of itself, a macro file. It may seem like the XLM and XML formats are similar since their file extensions look the same, but they're actually two entirely different file formats. How to Open an XLM File It's important to take great care when opening executable file formats like .XLM files that you may have received via email or downloaded from websites you're not familiar with. Though Microsoft suggests that you no longer use them, you can still open XLM files with Microsoft Excel. Microsoft's free Excel Viewer lets you open XLM files without Microsoft Excel, as does LibreOffice Calc. If you find that an application on your PC does try to open the XLM file but it's the wrong application or if you would rather have another installed program open XLM files, learn how to change the default program for a specific file extension for making that change in Windows. How to Convert an XLM File You may be able to open an XLM file in Microsoft Excel or LibreOffice Calc and then save the open file to another similar format. If you're trying to figure out how to convert an XML file, learn more info on what an XML file is for information on how to do just that.