XLSB 2007 onwards
Readablespreadsheet
From Microsoft Office 2007 onwards, the core output format of MS Excel has been based on the Office Open XML (OOXML) file format. The ISO standard for OOXML is ISO/IEC DIS 29500. An OOXML file format consists of a compressed zip archive that is designated according to which file type it is. Further detail on OOXML can be found within fmt/189 - Microsoft Office Open XML.
Identify it
| Extensions | .xlsb |
|---|---|
| MIME types | application/vnd.ms-excel.sheet.binary.macroenabled.12 |
| PRONOM | fmt/595 |
| Wikidata | Q66759528 |
| Library of Congress | fdd000512 |
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Open it
- LibreOfficeOpen source
Convert it
| To | With | Fidelity | Command and losses |
|---|---|---|---|
| Office Open XML 2007 onwards | LibreOffice | Partial | soffice --headless --convert-to xlsx in.xlsbLayout may shift; macros and some features are not kept. |
| OpenDocument | LibreOffice | Partial | soffice --headless --convert-to ods in.xlsbLayout may shift; macros and some features are not kept. |
| LibreOffice | Partial | soffice --headless --convert-to pdf in.xlsbFixed layout: the document is no longer editable. | |
| CSV | LibreOffice | Lossy | soffice --headless --convert-to csv in.xlsbFirst sheet only, values only: formulas, formatting and other sheets are lost. |
Sources
From Converters (FFmpeg, ImageMagick, Pandoc, LibreOffice), Just Solve the File Format Problem (File Formats Wiki), PRONOM, Wikidata. Updated 2026-10-26.