Ext Decoder
Spreadsheet

.xls — Microsoft Excel 97-2003 Spreadsheet

The legacy binary format for Microsoft Excel spreadsheets, superseded by the XML-based .xlsx format.

Commonly opened with
  • Microsoft Excel
  • Google Sheets
  • LibreOffice Calc
Supported platforms
  • Windows
  • macOS
  • Linux
  • Web / Cross-platform
Editable?
Yes, with common software
Viewable without special tools?
Usually, yes
Commonly converted to
  • .xlsx
  • .csv
  • .pdf
Inherent format risk
Use some caution
Safety guidance (not a guarantee)

This format can contain macros or embedded scripts that run code when enabled. Keep macros disabled unless you trust the source and specifically expect them.

Check another filename

No upload, no sign-up — everything is analyzed locally in your browser.

Frequently asked questions

What is a .xls file?

The legacy binary format for Microsoft Excel spreadsheets, superseded by the XML-based .xlsx format.

Can I edit a .xls file?

Yes — .xls files are commonly editable with software such as Microsoft Excel.

Does having a .xls extension mean the file is safe?

No single extension can guarantee that. This format can contain macros or embedded scripts that run code when enabled. Keep macros disabled unless you trust the source and specifically expect them. Always consider where the file came from, not just its name.

Privacy: The lookup above runs entirely in your browser. Nothing you type is uploaded, logged, or sent anywhere.

← Back to the file extension lookup tool