What is a .xlsm file?
A .xlsm file is an excel spreadsheet. Its registered MIME type is application/vnd.ms-excel.sheet.macroEnabled.12, which places it in the application or document family of formats.
Technically it is a specialised form of application/vnd.openxmlformats-officedocument.spreadsheetml.sheet (the .xlsx format), so tools that understand that format can often read at least part of it.
XLSM is a binary format: the contents are not readable text, so opening it in a text editor shows scrambled characters.
XLSM file format details
| Extension | .xlsm |
|---|---|
| Format | Excel spreadsheet |
| MIME type | application/vnd.ms-excel.sheet.macroenabled.12, application/vnd.ms-excel.sheet.macroEnabled.12 |
| Category | Application or document |
| Text or binary | Binary |
| Based on | application/vnd.openxmlformats-officedocument.spreadsheetml.sheet |
| File signature | None fixed |
| Registered with IANA | No |
| Other extensions | None |
How to open XLSM files
| Windows | XLSM files (Excel spreadsheet) are made by specific software. The reliable way to open one is with the program that created it; a generic viewer will only show raw data. |
|---|---|
| Mac | The same applies on a Mac: look for a Mac version of the program that makes XLSM files. |
| iPhone and iPad | Phones rarely open this type of file directly. The viewer above can show what is inside it without installing anything. |
| Android | The same applies on Android. The viewer above shows the first bytes of the file so you can confirm what it is. |
Convert XLSM files
TapToConvert converts XLSM files in your browser, without uploading them. Open the XLSM converter, or go straight to a conversion:
XLSM file FAQ
What is a .xlsm file?
A .xlsm file is an excel spreadsheet, with the MIME type application/vnd.ms-excel.sheet.macroEnabled.12.
How do I open a .xlsm file?
With the program that created it. The viewer on this page shows what is inside without installing anything.
Is a .xlsm file safe to open?
XLSM files hold data rather than programs, but any file from an unknown source can be crafted to exploit the software that opens it. Keep that software up to date. The viewer on this page only reads the bytes and never runs anything.
What is the MIME type of .xlsm?
application/vnd.ms-excel.sheet.macroEnabled.12, and it is also seen as application/vnd.ms-excel.sheet.macroEnabled.12. Web servers send this type so browsers know how to handle the file.
Is XLSM a text or binary format?
Binary. Its contents are not readable as text.
File type facts come from the IANA media type registry, the mime-db project and the freedesktop.org shared MIME database.