.XLSMHTML File Extension
File TypeMicrosoft Excel MIME HTML Spreadsheet
What is an XLSMHTML file?
An XLSMHTML file is an archived MIME HTML spreadsheet saved by Microsoft Excel (2007 and earlier), a common spreadsheet application. It contains HTML code that represents the spreadsheet in a format similar to the original .XLS file. XLSMHTML files are used for viewing published spreadsheets in a web browser.
NOTE: To create a webpage version of your document in Excel 365, select, then choose the "Single File Web Page (*.mht, *.mhtml)" option from the dropdown menu.
How do I open an XLSMHTML file?
Unfortunately, there are no known applications that fully support the XLSMHTML format since Microsoft Excel dropped support for it.