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PurePDF

Encrypt PDF

Add a password and encryption to protect a PDF.

  • 100% Private
  • No Limits
  • Works Offline
Choose PDF file

or drag and drop here

Add real AES-256 password protection to a PDF using qpdf — the same trusted engine many desktop and server tools rely on — compiled to run entirely in your browser.

How to use this tool

  1. 1

    Upload your PDF

    Click the upload area or drag in the document you want to protect.

  2. 2

    Set a password

    Type a password and confirm it.

  3. 3

    Encrypt and download

    Your password-protected PDF downloads immediately — nothing is uploaded first.

Why use this tool

Nothing leaves your device

Encryption runs locally via qpdf compiled to WebAssembly — your document and password never touch a server.

Real AES-256 encryption

Uses qpdf's standard security handler, not a simplified or custom scheme.

One password, fully protected

The same password is required to open and to change permissions — simple to use and remember.

Common use cases

Protect sensitive documents

Add a password before emailing contracts, financial statements, or personal records.

Secure an archive

Password-protect documents before storing them long-term.

Share safely

Send a protected file and share the password separately through a different channel.

Pro tips

  • There's no way to recover a lost password — store it in a password manager.
  • Share the password through a different channel than the file itself (e.g. a text message, not the same email).
  • Use Remove Password later if you no longer need the protection.

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