PDF Encrypt
PDF Encrypt is a free, open-source utility for password-protecting PDF files. It allows users to encrypt standard PDF documents without purchasing expensive commercial software or uploading confidential files to third-party servers. The app uses the iTextPDF open source library for encryption operations and is released under the AGPL license. It is primarily designed for Windows systems and includes command-line argument support for automation in existing workflows.
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1 suggestionPDF Encrypt appears to be a Windows-only application — the official website (pdfencrypt.net) describes it as a "native Windows app" and provides installers only for Windows 7, 8, 10, and 11. The latest release dates to 2023. There is no mention of a macOS build, native or otherwise, in the project documentation or GitHub repository. This means the Intel version running under Rosetta 2 today will stop working entirely when Apple removes Rosetta in macOS 28 (late 2027). If you are a macOS user who needs PDF encryption, macOS includes native PDF encryption built into Preview (the system's standard PDF viewer) — select a PDF, go to File → Print, then choose "PDF → Encrypt PDF" from the dropdown. This requires no additional software. For more advanced encryption workflows or automation via the command line, look at the free PDFtk or commercial tools like Adobe Acrobat Pro, both of which offer macOS builds.
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