There is currently verified online-only WKF converter. Any website that claims "Free online WKF to PDF converter – No download required" is fraudulent. Verification requires local processing because:
Using the KiCad WKF File Converter is straightforward: wkf file converter verified
Industrial plants used Lotus for shift logs and inventory tracking for decades. Many CNC machines and legacy ERP systems exported reports as .WK1 or .WK4 . Converting these to modern SQL databases requires a tool that respects the fixed-width column architecture of old WK files. There is currently verified online-only WKF converter