Convert XLS to XLSX
Bring old Excel 97–2003 workbooks into the modern .xlsx format — every sheet, formula, colour, merged cell and chart kept, so the file opens anywhere without compatibility mode.
- Deleted right after converting
- Encrypted transfer, deleted instantly
- No signup, no watermark
How it works
Add XLS files
Drop one or several .xls files onto the page — binary .xlsb workbooks work too.
Convert
One click — each workbook is rebuilt in the Office Open XML format, sheet by sheet.
Download
An .xlsx for every file, or all of them together in a ZIP.
Frequently asked questions
Why convert XLS to XLSX?
An .xlsx is usually far smaller, holds 1,048,576 rows instead of 65,536, opens without compatibility mode, and is the format modern tools, imports and online services expect. Many of them no longer accept .xls at all.
What is kept?
Every sheet with its formulas, number formats, fonts, colours, borders, merged cells, column widths, frozen panes, conditional formatting, data validation, comments, charts and images.
Is my file uploaded?
It is sent to the conversion engine over an encrypted connection, converted, and deleted the moment your file is ready — nothing is stored, logged or shared. If the engine is ever unreachable, your browser converts the file instead and tells you exactly what it could not keep.
What about macros?
The .xlsx format cannot hold VBA macros, so they are not carried across. If the workbook depends on its macros, keep the original .xls alongside the converted file.
Some "XLS" files from websites won't open properly — will this help?
Often, yes. Many web apps export an HTML table or an XML file and name it .xls. Those are read for what they really are and saved as a genuine .xlsx workbook.
What about password-protected files?
The password has to be removed first — open the file, remove it under File → Info → Protect Workbook (or File → Properties → Security in LibreOffice), save, and convert again. Sheet protection without a password is kept.
Good to know: VBA macros are not carried into .xlsx. Files up to 50 MB each. If the conversion engine is unreachable, the browser fallback keeps values, formulas, number formats, merged cells and column widths but not fonts, colours or charts.