The National Archives
Search our website
  • Search our website
  • Search our records
Image of software box and CD PRONOM
Welcome (PRONOM  home page) About PRONOM Add an entry
Search Help - opens in a new window Information resources - opens in a new window

*Details: File format summary



Search by keyword Search by file format Search by PUID Search by software Search by vendor Search by lifecycles Search by Migration Pathway

Details for:

Save as... XML | CSV Printer friendly version


Name Microsoft Excel 2.x Worksheet (xls)
Version 2
Other names Microsoft Excel Worksheet (2.1)
Identifiers MIME:  application/
Apple Uniform Type Identifier:
PUID:  fmt/55
Classification Spreadsheet
Disclosure None
Description The Binary Interchange File Format (BIFF) is a spreadsheet file format developed by Microsoft. BIFF 2 is the native file format of Microsoft Excel 2.1 for Windows. The format is proprietary and Microsoft does not make details of its structure public. The information contained here is derived primarily from's reverse-engineered documentation of the format, and should not therefore be regarded as definitive. BIFF is a stream based format, and a BIFF 2 file comprises a single worksheet stream, containing a Beginning of File (BOF) record, followed by a series of Worksheet records, and terminated by an End of File (EOF) record.
Orientation Binary
Byte order Little-endian (Intel)
Related file formats Is previous version of Microsoft Excel 3.0 Worksheet (xls) (3)
Is supertype of Microsoft Excel Chart (2.x)
Is supertype of Microsoft Excel Macro (2.x)
Technical Environment  
Supported until  
Format Risk  
Developed by Microsoft Corporation
Supported by Microsoft Corporation
Source Digital Preservation Department / The National Archives
Source date 11 Mar 2005
Source description  
Last updated 19 Jul 2013
Top of page Top of page
The National Archives Newsletter Icon

Send me The National Archives’ newsletter

A monthly round-up of news, blogs, offers and events.