Just discovered Binary (XLSB) format. If I want to switch file back to XLSM format later, will anything have been lost?

[d0rian]

I just found out about the XLSB (Excel Binary) file format, with biggest advantage being file size.
Indeed, saving my 17 MB XLSM file as an XLSB reduced it to 6 MB (a third the size!)

I don't think any of the drawbacks of the XLSB format apply to me, but I want to know this: if I save my file as an XLSB and then weeks down the line discover something about the format I don't like, is reverting as simple as re-saving the file as an XLSM? Or does the initial conversion from XLSM > XLSB strip out something that can't be recovered by simply re-saving as an XLSM?

As a test, I took my original XLSM file of 17,746,600 bytes in size and:
1) Saved it as XLSB > resulted in file size of 6,053,996 bytes
2) Then immediately saved that back as XLSM > 17,746,650 byes (tiny 50-byte dif from original, inconsequential I assume)

So it appears as though it's restoring more or less the same XLSM file as I started with, but don't want to discover later that I'm wrong and that something I needed is unrecoverable.

 

[JLGWhiz]

Excerpt from Professor Excel

The main disadvantage: Binary Excel files can contain VBA macros. So unless you don’t know the origin of a file, please consider well before opening them. Besides that: All the other disadvantages seem minor.

Advantages
Smaller file size.
Faster opening and closing of files.
Formulas with more than 8192 characters allowed.
Can use and save all the functions available in Excel.

Disadvantages
Security: Files can contain VBA code whereas XLSX files can’t.
You can’t change the Excel ribbon.
Some third party tools (e.g. OpenOffice) might not be able to open your file.
You can’t open your files with Excel 2003 or earlier (which nowadays should not be a problem any more…).
Not very well known. So people might get confused receiving XLSB files from you.

It appears that xlsb is less universal than standard xlsx or xlsm files for sharing , or exporting and importing.. overall, for personal use, it is a space saver.

 

[d0rian]

Yes, I know that, but it's not really responsive to the Q I asked, which was about saving an XLSM as an XLSB, and then back to XLSM...

 

[JLGWhiz]

Yes, I know that, but it's not really responsive to the Q I asked, which was about saving an XLSM as an XLSB, and then back to XLSM...

I am no expert, but from what I read, the main difference is the file srorage format with no data being lost between the file types, regardless of which directinon you go when saving the file. Remember, when you open a file and it loads into the Excel application, The application determines how the data is managed, not the file format. The file format only affects how the data is stored when the file is closed and how it is retrieved when opening it. So it should not lose anything going in either directiion except some kbs of programmatic stuff that applies to file formatting.