XLS to CSV, convert old Excel 97 to 2003 workbooks

XLS is the binary workbook format Excel used from 1997 until 2007. Many accounting systems, bank portals and older ERP exports still produce it, and plenty of modern tools refuse to read it. Turning it into CSV gives you a plain text file that any database, script or import screen accepts.

XlsConverter decodes the binary file structure itself, so you do not need a copy of Excel on hand. If your source is the newer Open XML format, use the XLSX to CSV converter instead, and if you want to keep a real workbook, upgrade with XLS to XLSX.

How to convert XLS to CSV in three steps

1. 1Upload your .xls workbook or drop several files at once.
2. 2Pick the sheet, the delimiter and the text encoding.
3. 3Convert and download the CSV, or a ZIP with one CSV per sheet.

Code pages and the 65,536 row ceiling in old XLS files

An XLS file written by Excel 2000 on a Western European machine stores text in the Windows 1252 code page, while files from Eastern Europe or Asia may use 1250, 1251 or Shift JIS. A converter that ignores the code page record turns names like Müller or Łódź into question marks. XlsConverter reads the codepage record from the workbook and writes the CSV in true UTF-8, so the characters survive.

The XLS format stops at 65,536 rows and 256 columns per sheet. When an older system hit that limit it usually spilled the data into Sheet2, Sheet3 and so on. Exporting all sheets at once gives you every part, and you can join them back together in one CSV with the merge sheets option or convert them later with CSV to XLSX into a single modern sheet.

CSV has no data types, so every cell becomes text. Dates stored as serial numbers (45382 is 2024-03-31) are formatted on the way out, formulas are replaced by their last calculated values, and long account numbers or ZIP codes keep their leading zeros because we write the displayed value, not a rounded number. If you need the types preserved for a program, XLS to JSON or XLS to SQL are better targets.