XLS converter
Convert your XLS files to any format.
What is a XLS file?
XLS is the legacy Excel format — a binary file superseded by XLSX in 2007, still floating around in old templates and archives.
First released in 1987 by Microsoft, it uses lossless compression and no transparency, which makes it best suited to old Excel spreadsheets from Office 97-2003 that newer apps struggle to open.
Drop a XLS file below to see every available conversion. Files are processed server-side using LibreOffice and deleted immediately after — never stored.
Advantages of the XLS format
Opens in very old software
XLS is understood by Excel versions going back to the 1980s, making it the safest bet when a spreadsheet must open on genuinely ancient software.
Widely recognized
Even though XLSX has been the default since 2007, most spreadsheet apps and viewers still open .xls files without issue.
Simple binary structure
Its compound-file format is well understood by conversion tools, so cells, formulas and formatting extract reliably.
Convert XLS to…
Pick a target format — your XLS file will be converted server-side using LibreOffice.
XLS: frequently asked questions
What's the difference between XLS and XLSX?
XLS is the older binary format used by Excel 97-2003; XLSX, introduced in 2007, is a modern ZIP-based XML format that's smaller and more robust. Converting XLS to XLSX brings an old file up to the current standard.
Why won't my .xls file open in some apps?
Some newer or web-based spreadsheet apps have dropped support for the legacy binary format. Converting to XLSX guarantees compatibility everywhere.
Will formulas be preserved when converting XLS?
Formulas, cell formatting and multiple sheets carry over well. Very old macros specific to the binary format may not survive.
Is XLS still used today?
Rarely for new spreadsheets, but it still appears in old templates, archives and legacy data exports created before 2007.