ODS vs XLSX: OpenDocument Spreadsheets Versus Excel
ODS is LibreOffice and OpenOffice's native spreadsheet format, built on the same open OpenDocument standard as ODT, and it holds the same relative position to XLSX that ODT holds to DOCX. The underlying logic for choosing between them follows the same pattern too: both are fully capable modern formats, and the practical decision mostly comes down to which spreadsheet software you and the people you're sharing with actually use.
Feature parity is genuinely close
ODS supports formulas, multiple sheets, cell formatting, charts, and the general range of features a modern spreadsheet needs — feature-for-feature, it's a close match to what XLSX offers, since both are built around the same fundamental idea of a full-featured, XML-based spreadsheet format rather than a bare data-storage format like CSV. Neither format has some structural capability the other fundamentally lacks; the comparison here is much more about ecosystem and convention than raw capability.
Where formula compatibility gets specifically tricky
Complex formulas, especially ones using more advanced or less universally standardized functions, occasionally don't translate perfectly between Excel's formula engine and LibreOffice/OpenOffice's formula engine when a spreadsheet moves between XLSX and ODS. Basic formulas (sums, averages, simple lookups) generally convert without issue, but for a spreadsheet with genuinely complex, advanced formula logic, it's worth verifying the formulas still produce identical results after converting between the two formats, rather than assuming a perfect match by default.
Why XLSX remains the more common convention
Excel's wider general market presence means XLSX is more frequently the default expected format in most professional and business contexts, similar to DOCX's position relative to ODT — this is primarily a matter of installed base and convention rather than ODS being technically deficient in comparison.
Where ODS makes the most sense
For anyone using LibreOffice or OpenOffice as their primary spreadsheet tool, ODS as the native format avoids relying on a compatibility layer for every save, and sidesteps the kind of subtle formula-translation risk that comes from consistently working in a non-native format. Organizations and contexts that specifically prioritize open, non-proprietary standards also tend to favor ODS for the same underlying reasons that lead them to favor ODT for documents.
A practical way to decide
If you're working primarily in LibreOffice or OpenOffice, ODS as your native format is the more natural choice. If you're sharing with someone you know uses Excel, or working somewhere XLSX is the clear expected convention, saving directly in XLSX avoids depending on cross-format compatibility to get formulas and formatting exactly right. For a spreadsheet with complex formulas that needs to move between the two ecosystems regardless, a quick check that key calculated values match after converting is a sensible precaution rather than an assumption.
Whichever spreadsheet format you're working in, Excel to PDF handles converting either ODS or XLSX into a fixed, shareable PDF once the spreadsheet is ready to distribute as a finished report rather than an editable working file.