Microsoft Excel 2000-2003 Workbook (xls) 8X
Readablespreadsheet · also known as Microsoft Excel Workbook (XP-2003), Microsoft Excel Workbook (2002-2003)
The Binary Interchange File Format (BIFF) is a spreadsheet file format developed by Microsoft. BIFF 8X is a native file format of Microsoft Excel XP. The format is proprietary and Microsoft does not make details of its structure public. The information here is derived primarily from OpenOffice.org's reverse-engineered documentation of the format and should not therefore be regarded as definitive. BIFF 8X is based on Microsoft’s generic OLE2 Compound Document Format. An Excel workbook is stored as a ‘Book’ stream within a Compound Document Format file. The Book stream comprises a Workbook Globals Substream, containing a Beginning of File (BOF) record, the Workbook global records, and terminated by an End of File (EOF) record. This is followed by one or more Worksheet substreams, containing a Beginning of File (BOF) record, the worksheet records, and terminated by an End of File (EOF) record. The format remained unchanged with the release of Excel 2003.
Identify it
Not sure your file is this? Identify it from its first bytes, in your browser.
Open it
- CytoscapeOpen source
- LibreOfficeOpen source
Convert it
| To | With | Fidelity | Command and losses |
|---|---|---|---|
| Microsoft Excel for Windows 2007 onwards | LibreOffice | Partial | soffice --headless --convert-to xlsx in.xlsLayout may shift; macros and some features are not kept. |
| OpenDocument Spreadsheet file format family | LibreOffice | Partial | soffice --headless --convert-to ods in.xlsLayout may shift; macros and some features are not kept. |
| LibreOffice | Partial | soffice --headless --convert-to pdf in.xlsFixed layout: the document is no longer editable. | |
| Comma Separated Values | LibreOffice | Lossy | soffice --headless --convert-to csv in.xlsFirst sheet only, values only: formulas, formatting and other sheets are lost. |
Sources
From Converters (FFmpeg, ImageMagick, Pandoc, LibreOffice), PRONOM, Wikidata. Updated 2026-10-20.