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PDF Encrypt Tool

Password-protect a PDF with standard RC4-128 encryption. Set user and owner passwords, restrict printing, copying, or modifying — free and private.

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Accepted: .pdf,application/pdf

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Protect a PDF with a Password

The PDF Encrypt Tool adds a standards-compliant password and permissions layer to any PDF. It uses PDF 1.4's Standard Security Handler (Revision 3, RC4-128) — the same mechanism found in Acrobat, macOS Preview, and most desktop PDF editors.

Two Passwords, Two Purposes

  • User password — required just to open the file. Without it, readers refuse to display contents.
  • Owner password — required to change permissions. A recipient who only has the user password can view the file but not (cleanly) bypass printing / copying / modifying restrictions.

You can set one or both. If you leave the owner password empty, it defaults to the user password.

Permission Flags

  • Printing — disable to produce a view-only document.
  • Text / image copy — disable to prevent trivial extraction via select-and-copy.
  • Modification — disable to discourage form filling, annotation, or content edits.

Keep in mind that these are soft restrictions: a determined user with the right tools can strip them. Encryption protects against casual viewing, not against well-resourced attackers. For truly sensitive documents, consider full-file encryption (GPG, 7z AES-256) on top of the PDF.

Common Uses

  • Sending contracts or invoices by email with a handshake-shared password
  • Distributing review copies where printing or copying isn't desired
  • Meeting compliance requirements that mandate PDF password protection
  • Protecting personal records before uploading to shared storage

Privacy

All encryption happens in your browser using a compact inline MD5 + RC4 implementation. The PDF is never uploaded; neither are the passwords. Closing the tab erases everything.