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Secure files

Add a password to your PDF

Protect a PDF with modern AES-256 encryption so only people with the password can open it.

Protect PDF Security

Upload your files

Select the files you want to protect pdf and PaperKit will open the interactive workspace.

Drop files here

or click to browse from your computer

Add document access protection in one step

Protect PDF applies AES-256 password protection to the whole document, which is helpful when the file needs a basic access gate before sharing or archiving.

Because this version stays Python-only, the protection flow remains inside the same server-rendered PaperKit stack instead of handing the file off to a separate binary toolchain.

Use cases

  • Password-protect a PDF before external delivery.
  • Secure archived copies of sensitive packets.
  • Follow with Unlock PDF later when edits are needed.

Why use Protect PDF online

  • Apply AES-256 protection.
  • Secure the full document in one step.
  • Keep the workflow server-rendered and temporary.

How to use Protect PDF

Step 1

Upload one PDF.

Step 2

Enter and confirm the password.

Step 3

Download the protected PDF.

Protect PDF specs and limits

Accepted files
1 PDF
Encryption
AES-256
Output
1 protected PDF

Protect PDF FAQ

Can I protect an already-secured PDF?

This flow expects an unlocked PDF. Unlock the file first if you need to change the password.

Is the password stored in the job manifest?

No. PaperKit stores the job output, not the password text itself.

Related tools

Keep working in the same flow

Security

Unlock PDF

Remove PDF password protection when you have the valid password.

Open tool SecurityApplication
Security

Redact PDF

Search and blackout matching words or phrases in a PDF.

Open tool SecurityApplication
Optimize

Repair PDF

Run a repair pass that rewrites a PDF into a fresh normalized file.

Open tool Document Management

Security tools

More security PDF tools

If Protect PDF is one step in a longer workflow, these related security tools stay close by.

Security

Sign PDF

Add a visual signature block to a PDF in one server-side pass.

Open tool SecurityApplication