Convert WK1 to XLSX In Batch

Total Excel Converter lets you convert Lotus 1-2-3 WK1 spreadsheets into modern Microsoft Excel XLSX format. If you have legacy WK1 files that can no longer be opened in current versions of Excel, this tool will convert them in seconds — preserving your data, layout, and cell formatting.

Quick answer: To convert WK1 to XLSX, install Total Excel Converter, open the folder with your Lotus 1-2-3 WK1 files, select them, click the XLSX button, and press Start. The whole batch converts in seconds, runs offline on your PC, and keeps your data, layout, and cell formatting intact.

What Is a WK1 File?

WK1 is the native spreadsheet format of Lotus 1-2-3, a program developed by Lotus Development Corporation (later acquired by IBM). Lotus 1-2-3 dominated the spreadsheet market throughout the 1980s and early 1990s before being overtaken by Microsoft Excel. The software was officially discontinued in 2014.

WK1 files store cell data, formulas, and basic formatting in a compact binary format. They use the .wk1 extension and correspond to Lotus 1-2-3 version 2.x. Related Lotus extensions include .WKS (v1), .WK2, .WK3, .WK4, and .123.

The problem: Microsoft Excel 2007 and later versions dropped native support for WK1 files. If you try to open a WK1 spreadsheet in a modern version of Excel, you will get an error. A dedicated converter is the most reliable way to access this data today.

How to Convert WK1 to XLSX

Download and install Total Excel Converter (free 30-day trial, 36 MB, Windows 7–11).
Select files. Use the built-in file explorer to navigate to the folder with your WK1 files. Check individual files or select an entire folder for batch conversion.
Choose XLSX as the output format in the toolbar and adjust settings if needed (page layout, naming conventions, sheet splitting).
Click Start and the converter will process all selected files. Single files convert in seconds; large batches of hundreds of files finish in minutes.

You can also generate a command-line script from any job to repeat it later without the GUI.

Watch this short video to get an idea of how it works:

WK1 vs XLSX: Format Comparison

	WK1 (Lotus 1-2-3)	XLSX (Microsoft Excel)
Developer	Lotus / IBM	Microsoft
First released	1983	2007
Status	Discontinued (2014)	Active, industry standard
Max columns	256	16,384
Max rows	8,192	1,048,576
Modern Excel support	No (dropped in Excel 2007)	Full native support
File structure	Binary	ZIP/XML (Open XML)

Other Lotus Formats We Support

Total Excel Converter handles the full family of Lotus 1-2-3 and legacy spreadsheet formats:

WKS, WK1, WK2, WK3, WK4 — all Lotus 1-2-3 versions
.123 — Lotus SmartSuite format
QPW — Corel Quattro Pro
ODS, XML, DBF, DIF, SYLK — and 20+ other input formats

All of them can be converted to XLSX, PDF, CSV, HTML, DOC, and many other output formats.

Try it free for 30 days. Personal licenses are just $49.90. A server version without GUI is also available. Contact us with any questions.

FAQ

What is a WK1 file?

WK1 is the spreadsheet format used by Lotus 1-2-3 version 2.x, a program originally developed by Lotus Development Corporation and later maintained by IBM. WK1 files contain cell data, formulas, and basic formatting stored in a compact binary format. The format was widely used in businesses throughout the 1980s and 1990s but has been discontinued since 2014.

Can I open WK1 files in modern Excel?

No. Microsoft dropped native support for Lotus 1-2-3 formats starting with Excel 2007. If you try to open a .wk1 file in Excel 2010, 2016, 2019, or 365, you will get an error or see no option to import it. You need a dedicated converter like Total Excel Converter to transform WK1 files into XLSX first.

How do I batch-convert multiple WK1 files to XLSX?

Install Total Excel Converter, open the built-in file explorer, navigate to the folder containing your WK1 files, and select them all (or check the folder to include every file). Choose XLSX as the target format, adjust any settings you need, and click Start. Hundreds of files can be converted in a single run.

Will I lose data or formatting when converting WK1 to XLSX?

Total Excel Converter preserves cell values, formulas, and basic formatting during conversion. However, Lotus 1-2-3 macros are not compatible with Excel and will not be converted. The overall structure of your spreadsheet, including rows, columns, and numeric data, will be accurately transferred to the XLSX file.

What is the difference between WK1, WK2, WK3, WK4, and .123 files?

These are all Lotus spreadsheet formats from different product versions. WKS is from version 1, WK1 from version 2, WK3 from version 3, WK4 from version 4, and .123 is the format used by later Lotus SmartSuite releases. Total Excel Converter supports all of these formats and can convert any of them to XLSX, PDF, CSV, and 20+ other formats.

Is there a command-line option for automated WK1 to XLSX conversion?

Yes. Total Excel Converter includes full command-line support. You can generate a ready-to-use .bat script directly from the GUI after setting up a conversion job, or write your own commands. This makes it easy to schedule conversions or integrate them into automated workflows.

Does Total Excel Converter work offline?

Yes. Total Excel Converter is a desktop application that runs entirely on your Windows PC (Windows 7 through 11). No internet connection is required for conversion, and your files never leave your computer. This is especially important for sensitive business data stored in legacy Lotus spreadsheets.