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.

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

1. Download and install Total Excel Converter (free 30-day trial, 36 MB, Windows 7–11).
2. 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.
3. Choose XLSX as the output format in the toolbar and adjust settings if needed (page layout, naming conventions, sheet splitting).
4. 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

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.

Total Excel Converter Customer Reviews 2026

"We discovered hundreds of WK1 files from the Lotus 1-2-3 era during a records audit. No modern software could open them. Total Excel Converter read every file and produced clean XLSX spreadsheets. Data integrity was perfect — even old date formats converted correctly."

Frank Morrison Archivist

"Inherited a legacy archive of WK1 financial models from the 1990s. The converter batch-processed the entire folder into XLSX files that open in Excel 365. Column widths, number formats, and formulas were preserved. Saved weeks of manual recreation."

Sandra Patel Financial Analyst

"One of the few tools that correctly reads WK1 files on Windows 10/11. Converted our client's legacy spreadsheets to XLSX without data loss. The command line interface is clean and scriptable. Would appreciate a log output option for audit trails."

Carlos Mendez IT Support Engineer

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