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XLS file format

Extension.xls
Categorydocuments
Programs
Microsoft Office
LibreOffice
Kingsoft Office
Google Docs
Main programMicrosoft Office
Description.xls The .xls format is the default file format for spreadsheets created in Microsoft Excel, particularly in versions before Excel 007. This binary file format can store data in cells organized in rows and columns, and it supports formulas, charts, graphs, and various formatting features to manipulate and visualize dataThe .xls format was commonly used in business, finance, and any field requiring data analysis and presentation but has since been largely replaced by the more advanced .xlsx format.
Technical detailsThe `.xls` format, primarily for Microsoft Excel versions before 2007, stores spreadsheet elements like worksheets, formulas, and macros. As a proprietary binary format by Microsoft, its undocumented internal structure made third-party software compatibility challenging. This format includes binary records encapsulating data, formatting, and embedded objects, supporting multiple worksheets, various functions, and inter-sheet referencing. `.xls` files may contain Visual Basic for Applications (VBA) macros, enabling automation and complex calculations. It's supported not just in Excel but also in applications like OpenOffice Calc, with options to convert between `.xls` and other formats like `.xlsx`. Despite security concerns with macros, `.xls` is still used, mainly for its compatibility with older Excel versions and legacy systems, although the newer `.xlsx` format, introduced in Office 2007 with XML and ZIP technologies, offers improved efficiency and security.
MIME type
application/vnd.ms-excel