Lotus 1-2-3 converter
Convert Lotus 1-2-3 workbooks from any release to Excel XLSX, with sheets, formulas, dates and graphs carried across.
.wk1 · .wk3 · .wk4 · .123
Format
About Lotus 1-2-3
Lotus 1-2-3 was the spreadsheet that sold the IBM PC. Release 1A saved .wks, Release 2 saved .wk1, Release 3 added multiple sheets in .wk3, Release 4 and 5 for Windows saved .wk4, and 1-2-3 97 through Millennium Edition saved .123. IBM withdrew the product in 2013, but research data, engineering models and accounting archives from that era are still stored in these files.
The older files start with 00 00 02 00 and a version word (04 04 for .wks, 06 04 for .wk1); the multi-sheet formats start with 00 00 1A 00 followed by a version in the 10 xx range. We check those bytes before converting, so a mislabelled file is refused instead of producing an empty workbook.
Our tests covered every extension in the family. Formulas came across as Excel formulas with cached results, including 920 in one survey workbook; sheets kept their names; dates became Excel dates; a named graph became an Excel scatter chart on its own sheet; and cell notes and drawn shapes survived. Range names were the gap: formulas still calculate, but Excel's Name Manager is empty.
Convert Lotus 1-2-3 to…
Common Lotus 1-2-3 problems
Excel says the Lotus file type is blocked.
Use /convert/lotus-to-xlsx instead of loosening Excel's File Block Settings.
Formulas that used range names now show plain cell references.
The names were not carried over. Recreate the important ones with Formulas → Define Name if other workbooks or macros refer to them.
A converted workbook has an extra sheet called Charts.
That sheet holds the Lotus graphs rebuilt as Excel charts. Move or restyle them, or delete the sheet if you only need the numbers.
You need the data in Python or R rather than Excel.
Convert to XLSX first, then read every sheet with pandas or readxl; neither reads Lotus files directly.