XLSM

What is an XLSM file?

An Excel workbook with macros attached.

What XLSM is

XLSM is a container: a wrapper that holds streams encoded by something else. It is used for editing.

The extension is .xlsm, and the full name is Excel Macro-Enabled Workbook. Both matter less than what the file can hold, which is what the rest of this page is about.

Where XLSM came from

Microsoft published it in 2007. The specification is ECMA-376.

Age is worth knowing here for one practical reason: the older a format is, the more programs have had time to learn it.

The specification is public

Anyone can implement it without asking permission or paying a licence, which is why it turns up in so many programs and why files written twenty years ago still open.

It can hold several pages in one file

A XLSM file is not limited to one page, which matters when converting to something that is: a target that holds one image produces one file per page, and the numbering it chooses is worth checking before you send it on.

It can contain macros

XLSM is allowed to carry executable code, and that is usually the reason somebody meets this extension at all: a mail gateway or a document portal rejected it. Converting to a format without macros is the usual way past that, and it does mean the macros are gone.

What kind of document it is

XLSM holds a spreadsheet: cells, formulas and the sheets around them.

That is what decides how it converts: a spreadsheet becomes a print area, and a print area is a decision somebody has to make about where the columns break.

What opens XLSM

Microsoft Excel reads it, and so do most programs of the same kind.

If a file will not open, the format is rarely the problem — it is more often that the program predates it. Converting to something older is the reliable way past that, and it is what the rest of this site is for.

Opening it in a browser

No browser reads it.

That is the single most common reason to convert it: not that the format is bad, but that the place you want to show the file cannot read it.

It is a working format

XLSM is meant to be opened and changed. Keep the file in this format for as long as the work is going on, and export from it whenever a finished copy is needed.

The facts, in one place

Identifiers and provenance for the XLSM format.
Extension.xlsm
Media typeapplication/vnd.ms-excel.sheet.macroEnabled.12
Published byMicrosoft
First published2007
SpecificationECMA-376

Converting XLSM to something else

Formats worth considering instead of XLSM