Google Sheets → Excel

My numbers or dates look different after converting to Excel

A date that read 13/04/2026 in Google Sheets now shows as 04/13/2026 in Excel, or a currency amount lost its symbol, or a number gained or dropped decimal places. Did the data change — or just how it’s shown?

What’s actually breaking

Most of the time, nothing in your data changed — only its display format did. A spreadsheet stores a number (say 46125 for a date, or 1234.5 for an amount) separately from the mask that decides how it’s shown (dd/mm/yyyy, $#,##0.00, and so on). Google Sheets and Excel don’t always carry those masks across identically, and both lean on the reader’s locale for defaults — so the same stored value can appear in a different date order or with a different currency symbol.

The distinction that matters: a cosmetic format shift leaves the underlying value intact (the date is still the same day, just written differently). A genuine value change — where a locale difference actually reinterprets the stored number — is rarer but far more serious.

How xlsx-for-ai handles it

xlsx-for-ai reads the stored value with its own engine, so it doesn’t silently corrupt the number underneath the format. When you read a workbook, the value it reports is the value the file holds — a display-format difference between Sheets and Excel is cosmetic and doesn’t change what’s stored.

We’re scoping this claim carefully rather than promising perfect format preservation. The honest statement is: we don’t change your values, and if a case ever arose where a locale shift would change a stored value rather than just its display, that’s exactly the kind of thing we disclose rather than pass through quietly. We are not claiming pixel-perfect reproduction of every number and date mask — some display drift between the two products is expected, and it’s cosmetic.

So if a date looks re-ordered after conversion, read the underlying value (xfa will show it): in almost every case it’s the same day, and you only need to reapply the date format you want in Excel.

How to check your file

  1. Add the connector to Claude once — open Settings → Connectors → Add custom connector and paste https://api.xlsx-for-ai.dev/mcp/claude. Full steps are on the developers page.
  2. Read the live Sheet by id. In Claude, ask: 
    Read this Google Sheet and convert it to an .xlsx, with xfa.
Flag anything that won't survive the conversion:
https://docs.google.com/spreadsheets/d/YOUR_SHEET_ID/edit
    Reading a live Sheet is read-only and uses a read-only Google token you supply — see the developers page for the one-time setup.
  3. Or skip the token — in Google Sheets choose File → Download → Microsoft Excel (.xlsx), then ask Claude to “read this file with xfa and tell me what it flagged.” Same reader, same flags.
  4. Read the flags. The result tells you exactly what it did and what it couldn’t carry across — so you review a short list instead of hunting for a wrong number later.
Quick sanity check: ask xfa for the raw value of a suspicious cell. If the stored number matches, it’s a formatting difference — fix it with Format → Cells in Excel, and your data is untouched.

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