Reducing Excel File Size

Recently, a customer of mine has requested my help for an excel issue. They had Excel.xls file of around 10 megs. This is not an issue per se, but it was busting their outlook file sending limits.

Shrinking the file by changing the extension to xlsx, or xlsm was working, it did shrink the file by 70% or 3megs, but did not fit their requirement since we could not assume that our users were not using excel 2003 and could install the excel compatibility pack

I then analyzed their file using an analysis tool given to me by Microsoft Support (I provide the source code of that tool here. Some very hiddent worksheet was containing around 20000 lines of data as a lookup tables. Those were data that did not need to be sent in the first place.Therefore I suggested they move those very hidden worksheet as another document, only sending between users the actual data that needed to be sent. This data was usually around 20kb in size. Therefore getting a higher than 95% file size decrease.