WK1 File Extension
Lotus Worksheet
- File Type wk1
- Developer IBM
- Popularity
- Application Lotus 1-2-3
- Category Spreadsheet Files
- Format Binary
What is a WK1 file?
The WK1 file extension is linked to Lotus Worksheet and belongs to the Spreadsheet Files category, which includes 113 files.
With the creation of the Lotus Worksheet (WK1), IBM introduced file format along with 70 programs built for their use.
WK1 file support extends to various operating systems, including Windows, Mac OS and Linux. You can open a WK1 file using one of 7 programs, for example Lotus 1-2-3, OpenOffice Calc and LibreOffice Calc.
MIME types
- zz-application/zz-winassoc-123
- application/x-123,
- application/vnd.lotus-1-2-3
- application/lotus
- application/x-lotus123
Programs that support WK1 files
How to open a WK1 file?
The most common reason why a WK1 file cannot be opened is the absence of required software. To fix this, select a compatible program from the list. Then visit the official developer website via the provided link, download the program, and install it on your system.
When it comes to opening and working with WK1 files, Lotus 1-2-3, OpenOffice Calc and LibreOffice Calc are the top choices for users. If you want the most recent release of Lotus 1-2-3, head over to the IBM site and download the version designed to run on all platforms.
When you finish installing Lotus 1-2-3, the system will automatically launch WK1 files with it.
Set Lotus 1-2-3 to open WK1 by default
Changing Default Programs in Windows
- Start by right-clicking on your WK1 file and selecting the "Open With" option. From there, click "Choose another app" to continue;
- Find the Lotus 1-2-3 application in the pop-up window and select it as your preferred program;
- Select the "Always use this application" check box and click "OK" to save your selection as the default application for opening WK1 files.
Change default apps on Mac
- Right-click or use Control + Left-click on the desired WK1 file to access the file’s context menu;
- Select "Open in application" and click "Other";
- At the bottom of the window, you will see the "Enable" menu. It is already set to the default option, "Recommended Programs";
- Within this menu, select "All Programs" and then search for Lotus 1-2-3. Check the box next to "Always open in app" to make it the default program.
Easy WK1 Troubleshooting
When facing challenges with WK1 files, simple adjustments in your software can often solve the problem. Find helpful troubleshooting guidance below.
What Causes Lotus 1-2-3 to Crash Frequently?
Lotus 1-2-3 crashes can be attributed to outdated software. Make sure you have installed the latest updates for IBM products.
Restarting your computer is often an effective solution to resolve various common problems. Therefore, it is recommended to do so before making any changes to the software configuration.
How can I restore a damaged WK1 file?
Use a recovery program to open the damaged WK1 file and navigate to the "Repair" menu item. Then wait for the recovery process to complete, which allows you to automatically repair corrupted spreadsheet files.
What are the signs that my WK1 file is damaged?
Common indications of damaged WK1 spreadsheet files are:
- Editing the archive in Lotus 1-2-3 results in slow or unresponsive behavior;
- File hangs or crashes in Lotus 1-2-3 or other programs;
- The file does not open or opens with errors;
- Unexplained increase in WK1 file size;
- Working with the file triggers the display of error messages;
How to edit a WK1 file?
To edit WK1 files, it is essential to install software that supports not only viewing but also editing the spreadsheet files. Online WK1 editors provide limited functionality compared to full-featured software for Lotus Worksheet.
Best WK1 editors in 2026
After analyzing the criteria, we have created a list of WK1 editors available for use.
| WK1 Editor Software | Developer | Platforms | Overall Rating |
|---|---|---|---|
| Microsoft Excel | Microsoft | Windows, Mac OS, Apple iOS, Android | 4.7 out of 5 (37 reviews) |
| OpenOffice Calc | OpenOffice | Windows, Mac OS, Linux | 4.6 out of 5 (44 reviews) |
| Corel Quattro Pro | Corel | Windows | 4.4 out of 5 (40 reviews) |
| LibreOffice Calc | TDF | Windows, Mac OS, Linux | 4.4 out of 5 (32 reviews) |
| Lotus 1-2-3 | IBM | Windows | 4.4 out of 5 (41 review) |
Convert to and from WK1
If working with a WK1 file is challenging, one solution is to convert it to formats like PDF, CSV, XLS, XLSX, MDB or other supported formats.
Keep in mind that converting a WK1 file may introduce some limitations, but the original format can often be restored.
Offline software options such as Lotus 1-2-3, OpenOffice Calc and LibreOffice Calc guarantee lossless conversion of WK1 files.