# Password Protect PDF: Arthize vs PDFtk

_Updated July 2026 · Arthize · https://arthize.com/vs/pdftk/protect-pdf_

To password-protect a PDF, Arthize offers a free, private password protect pdf with no watermark — a focused alternative to PDFtk. Protecting a PDF encrypts it with a password, so only people with the password can open the file — the encryption travels with the document.

## Arthize's password protect pdf vs PDFtk

PDFtk is a command-line PDF toolkit. PDFtk is a free command-line tool for scripted PDF operations.

**Arthize's approach:** Protecting a PDF encrypts it with a password, so only people with the password can open the file — the encryption travels with the document.

- A visual workspace instead of memorising command-line flags.
- 50+ tools live in one workspace, so you don't jump between single-purpose pages.
- Files are processed inside your private Arthize workspace and deleted after the job — never sold or used to train models.
- Handles conversion, OCR, signing and editing that PDFtk doesn't.

## How to password-protect a PDF with Arthize

Password protection encrypts the PDF so it can't be opened without the password.

The encryption travels with the file, unlike a folder lock that stays on your computer.

A separate permissions password can restrict printing or copying.

## How to password-protect a PDF with Arthize

1. **Open the protect tool** — Sign in and open the Protect tool.
2. **Add your PDF** — Upload the document you want to encrypt.
3. **Set a password** — Choose a strong open password and, optionally, a permissions password.
4. **Download** — Get an encrypted PDF that requires the password to open.

## FAQ

### Is Arthize a good PDFtk alternative to password-protect a PDF?

Yes. Protecting a PDF encrypts it with a password, so only people with the password can open the file — the encryption travels with the document. Arthize does it free with no watermark and deletes the file after the job. PDFtk is excellent for developers automating simple, repeatable PDF tasks from scripts.

### How do I password-protect a PDF?

Protecting a PDF encrypts it with a password, so only people with the password can open the file — the encryption travels with the document. On Arthize it's free with no watermark and processed privately.

### Is a password-protected PDF actually encrypted?

Protecting a PDF encrypts it with a password, so only people with the password can open the file — the encryption travels with the document. On Arthize it's free with no watermark and processed privately.