Google Sheets ↔ Excel: what breaks, and how we handle it.

Moving a spreadsheet between Google Sheets and Excel is a well-known source of quiet breakage — a formula that stops working, a column that collapses, a file that balloons to millions of empty rows.

These guides are deliberately honest. Each one names a real problem, explains what’s actually happening underneath, and says exactly what xlsx-for-ai does about it — whether that’s reading the value correctly, detecting the problem and telling you rather than guessing, or flagging a loss so it isn’t silent. Where a platform difference can’t be prevented, we say so plainly. We’d rather leave a guide unwritten than claim to solve something we don’t.

Formulas that don’t convert

• ARRAYFORMULA stopped working in Excel
  A Sheets-only wrapper with no Excel equivalent — we detect it and decline to guess rather than serve a wrong column.
• A spilled range (FILTER, SORT, UNIQUE) broke in Excel
  Dynamic arrays don’t always cross faithfully — we detect the spill and flag it instead of writing a shorter list.
• Google-Sheets-only functions break in Excel
  GOOGLEFINANCE, IMPORTRANGE and friends — we catch the cases that leave a tell, and we’re open about the one that doesn’t.
• A named function shows an error in Excel
  Custom named functions don’t exist in Excel — you get a visible error, not a silently wrong value.

Data that looks different

• Numbers or dates look different after converting
  Usually a display-format shift, not a data change — we don’t silently corrupt the stored value.
• Notes and comments when converting to Excel
  Two kinds of annotation, stored differently — we read both and disclose them so neither disappears unseen.

Files and CSV

• Huge empty rows or columns in a Sheets export
  An inflated used range bloats the file — we detect the phantom dimensions and flag them.
• CSV columns are wrong (semicolons instead of commas)
  Some locales export CSV with semicolons — we detect the delimiter and read the columns correctly.

How you use these

Every guide works the same way: add the xlsx-for-ai connector to Claude once, then either point it at your live Google Sheet by id (read-only, with a read-only Google token you supply) or hand it a downloaded export. It reads the file with its own engine and tells you what it did — and what it couldn’t carry across. See the setup steps →

More guides are on the way as we prove out each case — we add a problem here only once we actually handle it.