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Protect PDF

Add a password to your PDF file

Click or drop a PDF here

About PDF Protect

PDF Protect encrypts your PDF with the password you enter, using the @cantoo/pdf-lib library's standard PDF security handler entirely in your browser — your file is never uploaded to a server. The password is set as the document's user password (required to open it), while a separate, non-user-facing owner password retains full permissions; printing, editing, copying, and annotating are restricted for anyone opening it with the password you set.

How to use PDF Protect

  1. 1Click the upload area and select a PDF file from your device.
  2. 2Type a password into the field.
  3. 3Click 'Protect PDF' to encrypt the file with that password.
  4. 4Click 'Download' to save the password-protected PDF.

Frequently Asked Questions

Is PDF Protect free to use?

Yes, it's free with no signup required.

How secure is the encryption?

It uses the PDF standard security handler (RC4/AES depending on the source document's PDF version) via the pdf-lib encryption implementation. Anyone opening the file will be required to enter the password you set.

Will my file be uploaded to a server?

No, encryption happens entirely in your browser.

Can I set separate owner and user passwords or custom permissions?

The password you enter becomes the user password needed to open the file, and printing, editing, copying, and annotating are restricted by default. There's no UI yet to customize permissions or set a different owner password.

Tips & Tricks

  • ✓Remember your password — there's no recovery option, and losing it means losing access to the protected file.
  • ✓Use the PDF Unlock tool with the same password if you need to remove protection later.
  • ✓Since editing, copying, and printing restrictions are enforced via the PDF standard, a determined user with specialized software may still be able to bypass permission restrictions (though not the password itself) — don't treat this as airtight DRM.
  • ✓Test opening the downloaded file with your password in a PDF reader before sharing it, to confirm it was protected as expected.