Protect PDF (Add Password)
Password-protect a PDF with encryption.
Add a password to a PDF so only people who know it can open the document. Encryption (AES-256) runs entirely in your browser, so your file is never uploaded.
Drag & drop a PDF, or click to browse
Add a password so only people who have it can open the PDF.
AES-256 encryption, applied entirely in your browser — your PDF is never uploaded.
Runs entirely in your browser — nothing is uploaded.
How to use the protect pdf (add password)
- 1Upload a PDF.
- 2Choose a password.
- 3Download the protected PDF.
Frequently asked questions
Is my PDF uploaded?
No — encryption runs entirely in your browser (via qpdf compiled to WebAssembly), so your file never leaves your device.
What does the password do?
The PDF is encrypted with AES-256 so it can't be opened without the password you set.
Can I remove the password later?
Yes — use the Unlock PDF tool with the password to produce an unprotected copy.
Read the guide
How to Password-Protect a PDF (Free, AES-256)