What Is PDFEncrypt and What Does It Do?

PDFEncrypt is a free, open-source Windows desktop app that adds password protection and encryption to PDF files locally on your PC. It is a fit if you use Windows 7, 8, 10, or 11 and want to encrypt standard PDFs without buying Adobe Acrobat or uploading confidential documents to a third-party server. It is not a full PDF editor, and it is not a DRM system.

What PDFEncrypt actually does

The app encrypts PDF files using standard PDF encryption algorithms. Once a document is encrypted, its contents become unreadable, and an authorized user must supply the password before the file can be viewed in Adobe Reader or Adobe Acrobat.

Beyond the open password, PDFEncrypt lets you apply options and permissions to the PDF, such as restricting what a reader can do with the document. Encryption is handled by the iTextPDF open-source library, and the app itself is released under the AGPL license.

Two things follow from how it works:

• Everything stays on your machine. The app runs directly on your Windows PC, so you do not need to upload confidential PDFs to a third-party server for encryption.
• It targets standard PDFs. PDFEncrypt is built to encrypt any standard PDF document.

Who it is for

PDFEncrypt suits individuals and small teams who need to password-protect invoices, contracts, statements, or similar documents before sending them, and who would rather not pay for commercial software or hand files to an online service.

It is a weaker fit if you need to edit PDF content, manage documents across a large organization, or enforce access after a file has been opened. The project's own news post on DRM and PDFEncrypt addresses the common question of creating PDFs that open without a password but still cannot be copied — a signal that DRM-style control is a frequent point of confusion rather than a core feature.

Versions and downloads

PDFEncrypt is distributed in several forms, so you can pick based on how you manage Windows machines:

The latest version listed is 1.1.8462.22528, released in 2023. SHA1 checksums are published for the installer, the installer without .NET Framework, and the portable edition, so you can verify a download before running it.

There is also a beta MSI package for use with Windows Active Directory. It was built with the free version of Advanced Installer and tested on Windows 10 x64 and Windows 11 x64. Note that the MSI does not include the .NET Framework, so that dependency has to be handled separately in a managed deployment.

What to check before you rely on it

• Confirm the file opens with a password in Adobe Reader or Acrobat. That is the stated behavior, and it is the quickest end-to-end test of whether encryption worked as intended.
• Decide up front whether you need an open password, permissions, or both. These are different controls, and permissions alone do not stop someone who can already open the file.
• Keep the password recoverable. PDFEncrypt encrypts the document; it does not provide a way around a forgotten password.
• Check the .NET requirement if you plan to deploy the MSI or the installer-without-.NET build across multiple machines.

The project also ran a Capterra review promotion offering free gift cards to the first 85 reviewers, which is a marketing detail rather than a product capability.