XLSX To CSV

XLSX to CSV

When to use

Any time you need to read or grep the contents of an .xlsx file in text form. The Read tool cannot render .xlsx directly; convert to CSV first.

Single-sheet XLSX

LibreOffice headless conversion works:

libreoffice --headless --convert-to csv --outdir /path/to/outdir /path/to/input.xlsx

Output: outdir/input.csv (the active sheet only).

Multi-sheet XLSX

LibreOffice's --convert-to csv only emits the active sheet, so hidden sheets get dropped silently. For multi-sheet files use xlsx2csv via uvx (no permanent install needed):

uvx --from xlsx2csv xlsx2csv -a /path/to/input.xlsx /path/to/outdir/

Output: one CSV per sheet, named after the sheet (with spaces preserved).

If you don't know whether a file is multi-sheet, default to xlsx2csv — it handles single-sheet files fine too.

Files served with the wrong extension

Some tools deliver XLSX content with a .zip extension (e.g. Cryptio's Trial Balance download). Inspect with unzip -l file.zip — if you see xl/workbook.xml or [Content_Types].xml, it's an XLSX. Rename to .xlsx and convert as normal.

Pitfalls

• LibreOffice silently emits the active sheet only — running it on a multi-sheet file looks successful but discards hidden sheets. Always check sheet count via unzip -l file.xlsx | grep worksheets/sheet.
• xlsx2csv requires an output directory for -a; it will not write to stdout when emitting multiple sheets.
• Empty rows in the source are emitted as commas-only lines; filter with grep -v '^,*$' if they're noisy.