What is a WK1 file?
A .WK1 file is a legacy Lotus Worksheet created by Lotus 1-2-3. This software was a popular spreadsheet program in the 1980s and 1990s. The format was developed by Lotus Software, which was later acquired by IBM. A .WK1 file stores spreadsheet data in rows and columns. It also saves formulas, cell formatting, and basic charts.
How to open WK1 files?
Modern spreadsheet software usually cannot open .WK1 files. Modern versions of Microsoft Excel dropped support for this format. However, you can still open these files using free desktop tools. LibreOffice Calc and Apache OpenOffice Calc provide good compatibility for old Lotus files.
Best practices and troubleshooting
Because .WK1 is an obsolete format, you should convert these files to modern standards for long-term storage. If you want to use the file in modern software, convert it to .XLSX or .CSV. You can use convert.guru to easily and safely convert .WK1 files to .XLSX, .CSV, or .ODS.
Summary
viewer.online/wk1 analyzes .WK1 files to identify their exact format and creator software, shows which programs can open the file, and usually previews it. Because .WK1 can have multiple historical versions and variations, we recommend using viewer.online/wk1 to identify the actual format of your file. Ultimately, viewer.online/wk1 directly opens and previews .WK1 files in the browser, eliminating the need to install software or troubleshoot compatibility issues.