How to open .WK files on Mac
To open .WK files on Mac, if you have Microsoft Excel for Mac, try File → Open; if it does not import the file, move the file to a Windows PC with Excel and convert it there.
Step-by-step instructions
- If you have Microsoft Excel for Mac, try File → Open; if it does not import the file, move the file to a Windows PC with Excel and convert it there.
- As a fallback, ask the sender for a re-saved copy in .xlsx or .csv from a desktop spreadsheet program that can import Lotus 1-2-3 WK-family files.
Common issues
Excel says the file format is not valid or won’t open
“.wk” is a family label and may not match the exact Lotus 1-2-3 variant; some Excel versions import only certain variants (Excel documentation explicitly discusses Lotus files like .wk3).
- Make a copy of the file, then try opening it in a different Excel version (older versions may have broader Lotus import support).
- If you can determine the variant, try renaming the copy to .wk1, .wk3, or .wk4 and attempt open again.
- If it opens, immediately Save As .xlsx or export .csv to preserve access.
Garbage characters or missing formatting after import
Legacy Lotus/Symphony spreadsheets are binary and feature mapping to modern spreadsheets may be incomplete, especially for formatting, charts, or nonstandard encodings.
- After opening, compare totals and key cells against expected values; focus on recovering the data first.
- Try saving to .csv for clean data transfer (values only), then re-apply formatting in a modern spreadsheet.
File extension is “.wk” but software expects .wk1/.wk3/.wk4/.wks
Some tools and documentation refer to Lotus spreadsheets using more specific extensions (wk1/wk3/wk4/wks). A file may be mislabeled or renamed during email/backup transfers.
- Ask the sender what program created the file and whether it was Lotus 1-2-3 or Symphony.
- Make a backup copy and try renaming the extension to a WK-family extension and re-open in Excel or another importer.
Still can’t open your .WK file?
Recover a deleted or lost .WK file
If the file was deleted by mistake or the drive was formatted, data recovery software may be able to get it back. Stop writing to that drive right away, because new data can overwrite what you want to recover.
Windows software that recovers deleted or lost files from PCs and external drives such as HDDs, SSDs, USB drives and memory cards, after deletion, formatting or a crash.
Wondershare RecoveritWindows and Mac software that recovers deleted or lost files from computers and external drives such as HDDs, SSDs, USB drives and SD cards.
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Security note
WK-family Lotus spreadsheets are legacy binary files; treat them as untrusted input because old/complex parsers can have vulnerabilities, especially in very old office software.