What Excel is
An Excel workbook is a zip archive of XML parts describing sheets, cells, formulas, styles and charts. The .xlsx extension is that format; .xls is the older binary one from before 2007.
Finance, operations and anyone who received a file from finance or operations.
What ASP is
A two-dimensional VBScript array with one assignment per cell.
Classic ASP applications.
What changes when you convert Excel to ASP
Only the first sheet is read, and cells are read as the text Excel displays rather than the number underneath. That matters for dates: a cell showing 15/03/2026 arrives as that string, not as a serial number you would then have to decode.
Dimensioned to the exact size of the table, then filled cell by cell.
What carries over from Excel to ASP
Excel records 5 things about a table that ASP has no way to hold.
Excel distinguishes a number from the text of a number; ASP does not, so every value arrives as text and has to be re-parsed by whatever reads it next.
An empty cell and a missing one are the same thing in ASP, so a null and an empty string in the Excel both come out blank and can no longer be told apart.
A line break inside a cell ends the row in ASP, so line breaks are replaced rather than carried through.
ASP has no header row. The column names are repeated as keys on every record instead, which is why the result is bigger on disk than the table it came from.
Anything visual in the Excel - weight, alignment, colour, column widths - has no counterpart in ASP and is dropped. The values are what survives.