KillerPDF

KillerPDF is a free Windows PDF editor that covers what most people open Acrobat for: annotate, fill and sign forms, merge, split, reorder pages, OCR scans into searchable PDFs, compare two versions, print and flatten. GPLv3, no account, no telemetry, and processing stays on your PC.

Install it with winget install killerpdf, Chocolatey or the Microsoft Store, or grab the portable build that carries its own .NET runtime. OCR runs on bundled Tesseract, signatures work with a Windows certificate or .pfx file, and there's even a command line for batch jobs. No paid tier exists. Solo users and small offices on Windows: free. Larger orgs can push the installer machine-wide, but there's no vendor support contract; that's what Acrobat and Foxit still sell.

The catch: editing existing text is a cover-up, literally. It drops an opaque box over the old words and a new text box on top, and the help page says the original text stays in the file. Don't use it to hide anything: Save Flattened (pages become images) or use a real redaction tool like Stirling-PDF. It's Windows 10/11 x64 only, a young project with one main developer, and it checks GitHub for updates by default.