Convert XLSX to XLS, Free
Upload your XLSX file and get a XLS in seconds. No account, no watermark.
How to convert XLSX to XLS
While XLSX is the modern Excel format, some older enterprise software, legacy systems, and older versions of Excel (before 2007) only accept the older XLS binary format. Converting XLSX to XLS is necessary when submitting files to systems that have not been updated to handle XLSX.
BoltConverter converts your XLSX file to the older XLS binary format on its servers. Most spreadsheet data including formulas, formatting, and multiple sheets is preserved. Be aware that XLS has stricter row limits (65,536 rows maximum) and does not support some features added in newer Excel versions.
Upload your XLSX file
Click the upload area or drag your .xlsx file onto the page.
Conversion to XLS on the server
The XLSX file is converted to the binary XLS format. Sheets and formulas are preserved.
Download the XLS file
Save the .xls file for use with legacy systems or older Excel versions.
Frequently asked questions
Why would I need XLS instead of XLSX?
Older enterprise software, some government submission portals, and legacy accounting systems still require the older XLS format. If a system rejects your XLSX, converting to XLS often solves the problem.
Are there limitations in XLS that XLSX does not have?
Yes. XLS supports a maximum of 65,536 rows per sheet (versus over 1 million in XLSX) and 256 columns (versus 16,384 in XLSX). XLSX features like table styles and newer formula types may also not carry over fully.
Will formulas work after conversion?
Standard Excel formulas are preserved. Formulas that use functions introduced after Excel 2003 may not work in XLS.
Can LibreOffice open XLS files?
Yes. LibreOffice Calc fully supports XLS files. Both XLS and XLSX are interchangeable for most users.
What happens if my XLSX has more than 65,536 rows?
Rows beyond the XLS limit (65,536) will be truncated in the output. If your data exceeds this limit, stay with XLSX or split the data into multiple sheets.