XLS File Documentation

Files with the XLS extension are spreadsheets created in Microsoft Excel, usually containing one or more sheets that store data in table format. Files with the XLS extension may contain mathematical functions, charts, styles and formatting.

Newer versions of Microsoft Excel have replaced the XLS format with the XLSX extension. This is due to the fact that Excel started using XML formatting. Microsoft Excel is the most popular spreadsheet application.


Feature Value
File Extension .xls
File Type Binary File Format
Developed By Microsoft
Initial Release 1987
MIME Type application/vnd.ms-excel
Maximum Rows 65,536
Maximum Columns 256
Maximum Cell Size 32,767 characters
Supported Data Types Text, Numbers, Formulas, Dates, Hyperlinks, etc.
Compression None
Version Compatibility Compatible with Excel 97-2003; can be opened in newer versions
Text Encoding Limited UTF-8 support; primarily ANSI
Macros Support Yes (VBA)
Pivot Tables Yes
Embedded Objects Support Yes (Charts, Images, other Office files)
Password Protection Yes
Multi-Sheet Support Yes
Backward Compatibility Yes (with limitations)
Popular Usage Data Storage, Data Analysis, Reporting, Financial Modelling
Internal Directory Structure Workbook, Macros, Embedded Objects (if any)
External Dependencies Generally, none
Encryption Supported (Weak in older versions, stronger in files saved from newer Excel versions)
File Size Limit Typically limited by system memory, but practically capped at around 2GB for most systems
Data Validation Yes
Conditional Formatting Yes
Auto-Fill Functionality Yes
Formula Auditing Features Yes