Which MIME types are related to file extension ".xlsm"?
The .xlsm file extension is associated with 2 MIME types:
application/vnd.ms-excel.sheet.macroenabled.12, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.
A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.
About .xlsm Files
XLSM files are macro‐enabled Excel spreadsheets that use the Office Open XML format.
They can store data in cells, formulas, and charts. They also include embedded Visual Basic for Applications (VBA) code to automate tasks.
The standard MIME type is application/vnd.ms-excel.sheet.macroenabled.12. Another related MIME type is application/vnd.openxmlformats-officedocument.spreadsheetml.sheet; this one is often used for macro‐free spreadsheets, as noted by FilExt.com.
- Macro Automation: Run custom scripts to simplify repetitive tasks.
- Data Analysis: Perform complex calculations and data management.
- Office Integration: Seamlessly work with other Microsoft Office applications.
- Software Support: Best opened with Microsoft Excel; LibreOffice Calc may also open them with limited macro support.
Relationship between file extension and MIME type
A file extension is a suffix at the end of a filename that indicates what type of file it is. File extensions help both users and operating systems identify what application should be used to open the file.
File extensions are typically separated from the filename by a period (dot) and consist of 2-4 characters, though they can be longer. For example, in the filename "document.pdf", ".pdf" is the file extension.
File extensions are closely related to MIME types, as they both serve to identify the format of a file. However, while MIME types are used primarily by web browsers and servers, file extensions are used by operating systems and applications.
Associated MIME types
application/vnd.ms-excel.sheet.macroenabled.12, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
FAQs
What is the difference between an XLSM file and an XLSX file?
The primary difference is that XLSM files are macro-enabled and can contain Visual Basic for Applications (VBA) scripts, whereas standard xlsx files cannot store macros for security reasons. While both share the same XML-based structure, you must use the .xlsm extension if you need to save automation scripts within the workbook.
How do I open an XLSM file?
The best software to open .xlsm files is Microsoft Excel (version 2007 or newer). You can also open them with free alternatives like LibreOffice Calc, OpenOffice, or WPS Office, though complex macros may not function perfectly outside of the Microsoft ecosystem.
Are XLSM files safe to open?
Because .xlsm files contain executable code (macros), they can potentially carry malware or viruses. You should only click Enable Content to run the macros if you trust the source of the file; otherwise, it is safer to view the data in Excel's "Protected View" without enabling the scripts.
Can Google Sheets open XLSM files?
Yes, Google Sheets can import and view the data within an .xlsm file. However, because Google uses a different scripting language (Apps Script) than Microsoft (VBA), the macros inside the file will not run and are typically removed or ignored during conversion.
How do I convert an XLSM file to a standard XLSX file?
Open the file in Microsoft Excel, click on File, select Save As, and choose Excel Workbook (*.xlsx) from the file type dropdown menu. Be aware that saving as xlsx will permanently remove all macros and VBA code from the new file.
Why aren't the macros running in my XLSM file?
Excel disables macros by default to protect your computer. To run them, look for a yellow security warning bar below the ribbon and click Enable Content. If the bar does not appear, check your Macro Security settings in the Excel Trust Center.
What is the MIME type for XLSM files?
The specific MIME type for macro-enabled Excel sheets is application/vnd.ms-excel.sheet.macroenabled.12. Ensuring your server sends this header helps browsers identify the file correctly; you can learn more about configuring headers at mime-type.com.
Can I edit XLSM files on a Mac?
Yes, Excel for Mac fully supports creating and editing .xlsm files, including running VBA macros. However, if the macros rely on Windows-specific system commands (like ActiveX controls), they may cause errors when run on macOS.
General FAQ
What is a MIME type?
A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.
MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.
MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.
How do I find the MIME type for a file?
You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.
Why can one extension have multiple MIME types?
Different programs and historical usage may assign various MIME identifiers to the same file format. Listing them together helps maintain compatibility across tools.