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 Plain Text is
Plain text here means columns lined up with spaces, the way a command line tool prints a table.
Terminal output, log files, fixed-width exports from older systems.
What changes when you convert Excel to Plain Text
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.
Columns are padded to the widest value. Width is counted in display columns rather than characters, so a table containing Chinese, Japanese or Korean text still lines up: those glyphs occupy two columns in a monospace font.
What carries over from Excel to Plain Text
Excel records 4 things about a table that plain text has no way to hold.
Excel distinguishes a number from the text of a number; plain text 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 plain text, 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 plain text, so line breaks are replaced rather than carried through.
Anything visual in the Excel - weight, alignment, colour, column widths - has no counterpart in plain text and is dropped. The values are what survives.