Excel spreadsheet (xls)
The Excel Spreadsheet (XLS) file format has the .xls extension. This file type originates from Microsoft Excel. However, other spreadsheet software can be used to display these files as well. These include:
- OpenOffice
- WordPerfect
The XLS file format should not be confused with XLSX and XSLB.
MIME types
The following MIME types apply to this file format:
- application/msexcel
- application/xls
File signature
Microsoft Excel spreadsheets of version 97-2003 use the OLE Compound File (OLECF). These files therefore have the OLECF file signature.
The object stream of the OLECF containing a Excel spreadsheet contains the string "..." with some version.
Excel 97-2003 spreadsheets
The Excel 97-2007 Binary File format is stored in the OLECF using multiple streams:
- Workbook stream
Encryption
See Word Document (doc). Note: perhaps this section should be moved to a separate section about Microsoft Office encryption