Convert XLSX to ODS Online (OpenDocument Spreadsheet)

Two ZIP Packages With Different Maps of the Same Sheet

XLSX and ODS are both compressed packages containing XML and related files, but they organize a spreadsheet under different standards. Microsoft’s SpreadsheetML documentation says that an XLSX workbook has a <workbook> part containing sheet references, with each worksheet stored as its own XML file. The ODF 1.3 package specification likewise requires a ZIP file, but it requires META-INF/manifest.xml to list package files and their media types. An ODS package normally uses files such as content.xml for spreadsheet content and styles.xml for styles, each with ODF-defined root elements. Converting XLSX to ODS is therefore a translation from one structured package to another, not a rename from .xlsx to .ods. The grid of ordinary values can map cleanly, but every feature must be represented in the destination format’s own vocabulary.

That technical difference is useful to understand because both extensions can open as a ZIP archive even though their internal files are not interchangeable. ODF specifies that the mimetype file, when present, is the first ZIP entry and is not compressed; this gives an application a fast way to identify the package. It also requires the package manifest to describe the enclosed files, including encryption information where relevant. SpreadsheetML instead uses package relationships to connect a workbook to worksheet, chart, table, and other parts. A proper conversion builds a new ODF manifest, content, styles, and settings from what can be represented, rather than copying Excel’s XML into a differently named archive. That is why the converted file should be treated as a new working copy and checked before it replaces the Excel original.

How XLSX Cells Become ODF Content and Styles

An XLSX cell may carry a raw value, a type, a style reference, a formula, a comment, validation rules, and links to other workbook features. In SpreadsheetML, formula text is stored in a cell’s <f> element, and the last calculated result can be stored in <v>. ODF uses the OpenFormula rules for spreadsheet expressions, particularly through the table:formula attribute, so an everyday calculation has a destination even though its source syntax is not the same internal record. ODF 1.3 keeps document content and styles in named XML parts, rather than the SpreadsheetML collection of worksheet and style parts. A converter can reproduce ordinary formulas, values, number formats, row heights, column widths, and hyperlinks because both formats describe these ideas. It cannot safely create an ODF equivalent where the Excel feature has no counterpart or where the source depends on Microsoft-specific behavior.

Shared text is one small but revealing example. SpreadsheetML can use a shared-string table with a single occurrence of each unique string across all worksheets, while ODF stores document content through its own XML model. The wording in the cells can survive even though the storage layout changes completely. A formula is more delicate because Excel functions, named ranges, and calculation behavior have to be expressed under the ODF formula rules and then recalculated by the destination application. Microsoft classifies formulas themselves as supported in ODS, but its feature table marks local names, named expressions, and names referring to discontinuous ranges as only partly supported on a later return to Excel. The realistic goal is a working spreadsheet with correctly checked calculations, not byte-for-byte preservation of the original package.

Five Useful Gains and Real Trade-Offs in an ODS Copy

• Gain — a native OpenDocument file: ODS is the package format used by OpenDocument spreadsheet applications, with standards-defined content, styles, and manifest files.
• Keep — ordinary worksheet layout: Microsoft lists row heights, column widths, cell formatting, print ranges, and basic formulas as supported for ODS export.
• Lose — Excel table styling: Microsoft marks Excel table styles and total rows as not supported in ODS, so a formatted Excel table can become ordinary styled cells.
• Change — threaded discussion records: Excel threaded comments are converted to legacy comments on ODS save, so replies and modern collaboration details do not remain threaded.
• Risk — protected or signed content: Microsoft says password-protected sheets cannot be saved or opened as ODS, while digital signatures are removed when an ODS file is edited in Excel for the web.

Which Spreadsheet Apps Handle the Converted File

LibreOffice Calc and Apache OpenOffice Calc are the usual desktop destinations for an ODS file because ODS is their native spreadsheet format. Microsoft’s supported-file-formats guidance also names OpenOffice.org Calc and Google Docs as applications that use the OpenDocument Spreadsheet format, and says that Excel can open ODS files. Excel for Microsoft 365, Excel 2024, Excel 2021, Excel 2019, and Excel 2016 are covered by Microsoft’s current ODS compatibility tables, but opening a file is not a guarantee that every feature remains editable in the same form. Microsoft’s mobile compatibility article separately lists ODS as read-only rather than editable for the Android, iOS, and Windows Mobile versions of Excel. This matters when the intended editor is a phone or tablet: converting an XLSX to ODS can make it suitable for Calc, but it does not turn mobile Excel into a full ODS editor.

For a workbook that must travel back to Excel, test a round trip: open the new ODS in the target application, save a copy, then reopen that copy in Excel and compare the important sheets. Microsoft says row heights, column widths, cells, and print ranges should be supported, while hyperlink styling may differ. It also marks many advanced chart components as partial or unsupported, including unsupported PivotChart, chart-sheet, data-table, and several specialized chart features. A basic model made of values, formulas, and ordinary formatting is the portable case. A dashboard built from PivotTables, specialized chart objects, data connections, or co-authoring features needs a deliberate compatibility test before ODS becomes the shared master.

Documented Conversion Gaps That Need a Targeted Check

Dates before 1900 are a concrete, documented data problem rather than a cosmetic difference. Microsoft says that these dates do not save correctly when an Excel workbook is saved as ODS, so historical registers, archival timelines, and date-like identifiers need a test before conversion. Formula-based data validation is another partial-support area: Microsoft warns that some formula-type validation cannot be saved when the file returns to Excel. A documented LibreOffice bug report, number 102368, records a separate interoperability failure in which an Excel inline list validation such as "1,2,3,4" was not imported correctly by LibreOffice. That report is not evidence that every current Calc release fails in the same way, but it is a concrete reason to click each drop-down list in the converted file instead of assuming that a visible cell proves the validation rule survived.

Excel-specific layout features have equally clear causes. Microsoft marks table styles and total rows as unsupported, PivotTable calculated fields as unsupported, and PivotTable grouping and layout as only partially supported. It says an unsupported WordArt effect is converted to a text box, while gradient fills with more than two stops lose all stops after the first two when saved as ODS. These are transformations made because ODF does not offer the same feature or behavior, not signs that the converter randomly damaged a healthy file. The fix is feature-specific: convert final display objects to pictures when editability is not needed, rebuild a simple total as an ordinary formula, and check a PivotTable against its source data after opening in Calc. Keep the XLSX master whenever those Excel-only details are part of the file’s purpose.

Open XML Workbook and ODF Spreadsheet Compared

Answers Before You Replace an XLSX Working Copy

Will ordinary Excel formulas still work after XLSX to ODS conversion?
Usually, yes: Microsoft lists formulas as supported. Still compare totals and a few formula results in the destination application because formula text is translated into ODF’s OpenFormula model, and named formulas have narrower round-trip support.

Why are my Excel table colors or total row missing in the ODS file?
Microsoft marks Excel table styles and total rows as unsupported in ODS. Keep the original XLSX, or rebuild the visible total as an ordinary formula and apply standard cell formatting in the ODS copy.

Can I safely convert a password-protected worksheet to ODS?
No. Microsoft states that a password-protected sheet cannot be saved or opened in this conversion path. Remove protection only from a controlled copy if you have authority to do so, then keep the protected original separately.

Do dates before 1900 survive XLSX to ODS?
Do not assume so. Microsoft specifically says pre-1900 dates do not save correctly as ODS, so preserve those values as verified text or test a small copy before converting an entire historical sheet.