01
ADD YOUR XLS
Drop the XLS file into the box above or choose it from your device.
XLS → XLSX / online converter
XLS to XLSX Converter
Upgrade an old .xls workbook to the modern .xlsx format. The data of the first sheet is carried over as clean values.
01 / how to
How to convert XLS to XLSX
02
CONVERT TO XLSX
XLSX is already selected. Press Convert and wait a few seconds.
03
DOWNLOAD
Save the finished XLSX file. The original is deleted from our server.
02 / what you get
What happens to your data
Kept
- Rows of the first sheet, with the first row used as the header
- Dates become readable text, for example 2026-01-15
- Formulas are exported as the result they last calculated
- A clean Excel workbook with one sheet, where plain numbers are real numeric cells you can sum and sort
Good to know
- Only the first sheet is converted. Move the sheet you need to the front in Excel first.
- Colors, fonts, merged cells, charts and images are not part of the data and are dropped.
- Password-protected workbooks cannot be opened.
- The result is plain values on one sheet named Sheet1. There are no formulas, styles, column widths or charts.
- If you need formatting and formulas kept, use Save As in Excel instead.
03 / formats
XLS vs XLSX
XLS
An XLS file is the older Excel workbook format (Excel 97-2003). It still turns up in old exports and archives. Converting it gives you the first sheet as plain data (JSON keeps every sheet), or a modern XLSX.
Used in: Legacy Excel files · Old exports · Archives
XLSX
An XLSX file is a modern Excel workbook: sheets of cells with numbers, text, formulas and formatting. It is the default for spreadsheets today. Converting it gives you the first sheet as plain data (JSON keeps every sheet), so other tools can read it.
Used in: Excel · Business reports · Financial data
04 / more
More conversions
Have a different file? Open the main converter — it detects the format for you.