ODS is the OpenDocument Spreadsheet format — an open, ISO/IEC 26300-standardized XML schema that LibreOffice Calc and Apache OpenOffice save to by default. XLSX is Microsoft's Office Open XML equivalent used by Excel. Both formats are, structurally, a ZIP archive of XML files describing sheets, cells, styles, and formulas — but the two schemas encode formulas, cell styles, and workbook structure differently enough that a raw .ods file won't open natively in Excel without a translation step in between, and vice versa.
This conversion reads your ODS file using SheetJS, a library built specifically to understand the OpenDocument Spreadsheet schema alongside dozens of other spreadsheet formats, and extracts every worksheet along with each cell's actual value, data type, and formula. Formulas written using standard functions — SUM, AVERAGE, IF, VLOOKUP, COUNTIF and the rest of the common function library — use largely the same syntax across both ODF and OOXML, so they translate over as working, live formulas rather than being flattened into static values. The result is written out as a genuine .xlsx workbook, not a renamed or repackaged ODS file, so Excel opens it exactly the way it opens any other native workbook.
What doesn't reliably survive the jump is anything tied to the file format's own internals rather than the spreadsheet's data: Basic macros (LibreOffice's scripting language) have no equivalent in Excel's VBA and are not converted, and some ODS-specific formatting — particular border styles, certain conditional formatting rules, or chart objects built with Calc's drawing tools — may render slightly differently once opened in Excel's own style engine. For everyday spreadsheets — budgets, data exports, formula-driven reports, and simple formatted tables — the underlying data and formulas make the conversion cleanly and remain fully functional.
Once converted, Excel to CSV or Excel to PDF both work directly on the resulting .xlsx file.
