Split wk1 sheets

Download and install the latest version of Filestar.
Right click on one or more Wk1 file(s) on your desktop and select Convert with Filestar.
Type split sheets in the search box.
Press Split.

What is .wk1?

Name: Lotus Worksheet
Extension: .wk1
Format: Binary
Category: Spreadsheet
Developer: IBM
Description: Lotus Worksheet (wk1) is a file type used by the Lotus 1-2-3 spreadsheet application. It is a binary file format used to store worksheets, which can contain numerical and textual data, as well as formulas, charts, and images. It is now considered an obsolete file type and is replaced by the newer xlsx format.
MIME Type: application/vnd.lotus-1-2-3

Last updated October 3, 2026