What is the ODS file format?
Files with the .ods extension contain compressed spreadsheet files stored in an open format based on XML. Internally, an .ods file is a ZIP archive containing a set of XML documents - the main spreadsheet data lives in content.xml, while styles, metadata and settings are kept in separate files within the same package. A special uncompressed entry named mimetype at the start of the archive identifies the file to software as application/vnd.oasis.opendocument.spreadsheet.
The .ods standard is part of the OpenDocument Format (ODF) specification for office documents. It originated from the OpenOffice.org spreadsheet format and is currently developed and maintained by the independent standards body OASIS. The format was standardised as ODF 1.0 in 2005 and gained ISO/IEC 26300 recognition in 2006. It is an open alternative to proprietary formats such as .xls and .xlsx.
An .ods spreadsheet may include:
- 2D sets of tables with data
- Various formulas and functions processing that data
- Visualisations of the data, such as charts
- Macro functions (stored as Basic or JavaScript scripts)
.ods spreadsheets support a wide range of functionalities found in Microsoft Office formats, though the two are not identical - some advanced Excel features may not round-trip without adjustment. Modern versions of Microsoft Excel can open and save .ods files directly, without plugins. There are several office suites, including free ones, to which .ods is the native spreadsheet format, among them LibreOffice Calc and Apache OpenOffice Calc. The related extension .ots is used for .ods template files.
Security & safety
RISK: LOWODS files are generally safe data documents, with one caveat shared with all office formats: they can contain macros (LibreOffice Basic), which both LibreOffice and Excel block or prompt about by default - never enable macros in a spreadsheet you did not expect. Hyperlinks and external data links can point to malicious destinations, and in 2023-2025 spam campaigns occasionally used ODS attachments precisely because mail filters scrutinize them less than XLSM. Opening an ODS with macros disabled is safe.
Format details
in a nutshellPrograms that open ODS files
Windows4 apps
Microsoft Excel
Paid Open directly (File - Open) - ODS supported since Excel 2007 SP2, ODF 1.3 in Microsoft 365. Saving back as ODS may drop Excel-only features; Excel warns when it does. 
LibreOffice Calc
Open-source ODS is its native format - double-click after installing. The reference implementation; full fidelity. 
Apache OpenOffice Calc
Open-source Opens ODS natively, but the project receives only sporadic maintenance (still on ODF 1.2) - LibreOffice is the actively developed choice.
ONLYOFFICE Desktop Editors
Open-source Free desktop suite; opens and edits ODS, saves to ODS or XLSX. 
macOS2 apps
Microsoft Excel for Mac
Paid Opens ODS like the Windows version. Note: Apple's Numbers cannot open ODS files. 
Linux3 apps
Calligra Sheets
Open-source KDE office suite component with ODS as a native format; niche compared to LibreOffice. 
Android2 apps
Collabora Office
Open-source LibreOffice-based mobile app; opens and edits ODS with desktop-grade fidelity. 
Google Sheets
Free Upload the .ods to Google Drive and open - it converts to a Sheets document; download back as .ods or .xlsx via File - Download.
Microsoft 365 for the web (Excel)
Free Upload to OneDrive and open in Excel for the web with a free Microsoft account. Technical details
deep spec| Container format | ZIP archive (deflate-compressed package, .zip-compatible) |
| Primary content file | content.xml - holds all sheets, rows, cells, and formulas |
| Styles file | styles.xml - stores cell formatting, page layout, and font definitions |
| MIME type | application/vnd.oasis.opendocument.spreadsheet |
| Magic bytes | 50 4B 03 04 (ZIP local file header signature) at byte offset 0 |
| Format identifier entry | Uncompressed mimetype file at the start of the archive; MIME string readable as plain ASCII near byte offset 38 |
| Character encoding | UTF-8 (mandatory for all XML content within the package) |
| Formula standard | OpenFormula (standardised in ODF 1.2); defines function names, syntax and semantics independently of application |
| Template variant | .ots (OpenDocument Spreadsheet Template); same ZIP structure, signals that new documents are created from it |
| Flat XML variant | .fods (Flat ODS); single uncompressed XML file with no ZIP wrapper - human-readable and diff-friendly |
| Embedded objects | Charts, images, OLE objects, and drawing shapes stored as sub-packages or binary streams inside the ZIP |
| Macro storage | Scripts stored in Basic/ subdirectory; supported languages include LibreOffice Basic, JavaScript, BeanShell, and Python |
| Multiple-sheet support | A single .ods file can contain multiple named worksheets (spreadsheet tables) within one content.xml |
| Manifest file | META-INF/manifest.xml lists every file in the package with its MIME type and encryption status |
| Encryption support | Individual files within the ZIP can be encrypted using AES-256; the manifest records the algorithm and key-derivation parameters |
| Released | 2005 (ODF 1.0, OASIS); ISO/IEC 26300 since 2006; current major version ODF 1.3 (OASIS, 2021) |
| Open standard | Yes · royalty-free |
| Specification | www.oasis-open.org |
ODS conversions
Community Q&A
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