Toolnest

Protect PDF

Password-protect a PDF with AES-256 encryption and set print, copy and edit permissions. Encryption happens in your browser. Free.

or drop a PDF here

One PDF · up to 200 MB per file

Processed on your device – files are never uploaded

How to use Protect PDF

  1. Select or drop the PDF you want to protect.
  2. Type the password twice and choose the permissions.
  3. Press Protect PDF.
  4. Download the encrypted PDF and share the password separately.

Supported formats and limitations

Input
One PDF
Output
Encrypted PDF (AES-256)
Works on
Any modern browser on Windows, macOS, Linux, Android and iOS. JavaScript must be enabled.

Important limitations

Keep the password safe: nobody, including us, can recover it. Permission flags are honoured by standard PDF readers but are not a guarantee against determined misuse.

Privacy and file processing

Processed in your browser. The file is never uploaded to our server.

About Protect PDF

Protect PDF adds a password so only people who know it can open the document. Use it before emailing salary slips, medical reports, bank statements or contracts.

The file is encrypted with 256-bit AES, the strongest standard PDF encryption, by qpdf running inside your browser. You can also decide whether readers may print, copy text or edit the document. Neither the file nor the password is sent to any server.

Features

  • AES-256 encryption
  • Print, copy and edit permissions
  • Password strength hint and confirmation check
  • Runs locally with qpdf compiled to WebAssembly

Why use it

  • Keep sensitive documents private in transit
  • Works with Adobe Reader, browsers and phone PDF apps
  • Your password never leaves your device

How it works

qpdf (compiled to WebAssembly) encrypts the file with 256-bit AES, using your password as the user (open) password and a separate random owner password, and applies the permissions you chose. The password never leaves your browser.

Examples

Payslip

Input: payslip.pdf with password “Sun#2026”

Result: payslip-protected.pdf that asks for the password when opened.

Read-only contract

Input: Allow printing, block copying and editing

Result: A protected PDF with those permissions.

Protect PDF: frequently asked questions

What makes a good password?

At least 10 characters mixing words, numbers and symbols. Avoid names and dates of birth, and share the password through a different channel than the file.

Can I remove the password later?

Yes, with Unlock PDF, as long as you know the password.

Are permissions a strong security measure?

They are respected by standard readers, but the open password is what really protects the content.

Keep going

All tools