How to password-protect a PDF in 3 easy steps
- 1
Upload your PDF
Drag and drop the file into the upload area or click to select it from your device.
- 2
Set a strong password
Type a password of at least 6 characters. Use a mix of letters, numbers, and symbols — there is no way to recover a lost password.
- 3
Download the encrypted PDF
Click “Protect PDF”. The encrypted file downloads to your device, ready to share safely.
Why use the protect pdf tool from Super Utility Hub?
Protect a PDF with a password online for free. Encrypt your document so that a password is required to open it — ideal for contracts, invoices, salary slips, medical records, and any file that only specific people should read.
You choose the password; the file is encrypted on your device and then safe to send by email, cloud storage, or messaging apps. Anyone without the password sees only an error, and the encryption makes the content unreadable even if the file is intercepted.
Encryption happens locally in your browser using industry-standard AES with a 128-bit key. Your document and password never leave your computer. Free, unlimited, no account.
- Processes everything in your browser — no upload servers involved
- Free forever with unlimited uses
- Works on Windows, macOS, Linux, Android and iOS
- No watermark or branding on your output, ever
Frequently asked questions
Can a password-protected PDF be unlocked?
Without the password, no. That is the point of encryption. Keep the password in a password manager — if you lose it, the file cannot be recovered.
Is my password sent anywhere?
No. Encryption happens entirely in your browser. Your password and file never leave your device.
What encryption does the tool use?
The PDF is encrypted with standard 128-bit AES encryption, fully compatible with Adobe Acrobat Reader and every modern PDF viewer.
Can I remove the password later?
Yes — open the protected PDF with its password in the tool of your choice and save an unprotected copy, or use dedicated PDF unlock software.
Will the protected PDF still open on phones?
Yes. All mainstream PDF readers on iOS, Android, Windows, and macOS support password-protected PDFs.