Drop a PDF to password protect
AES-256 encryption — bank-grade security
Or drag and drop them here
Your files stay on your device · 0 uploads
PRIVATE PDF TOOL
Password Protect PDF
Add a password to your PDF. AES encryption applied locally — files never leave your device.
100% client-sideNo server involved
No uploadsYour files stay private
No account neededStart merging instantly
How it works
Merge your PDFs in just a few clicks.
1. Upload your PDF
Select the PDF you want to password-protect.
2. Set your password
Enter a strong password — it will be applied with AES-256 encryption.
3. Configure permissions
Optionally restrict printing, copying, or editing.
4. Download encrypted PDF
Your protected PDF downloads immediately, processed locally.
Your files never leave your device.
WhisperDocs runs entirely in your browser. All processing happens locally on your device, with no uploads, no accounts, and no tracking. Ever.
Processed in your browser
100% private
You stay in control
Common questions
Everything you need to know about merging PDF files with Encrypt PDF.
WhisperDocs uses AES-256 encryption, the same standard used by governments and financial institutions. It is the strongest PDF encryption available.
No. Encryption happens entirely in your browser using the Web Crypto API. Your file never leaves your device.
Yes. You can set a user password to restrict opening and an owner password to control permissions like printing and editing.
Yes — if you know the password, you can open and re-save the PDF without encryption using the same tool.
AES-256 encrypted PDFs cannot be recovered without the password. Store your password safely — WhisperDocs does not retain it.