Encrypt your documents with AES-256 military-grade security. 100% private, no server upload.
The PDF Protector by GrowthSyntax is a free, browser-based tool that encrypts any PDF document with AES-256 password protection — the same military-grade standard used by banks and government agencies. Set a user password to restrict document opening, an optional owner password to restrict editing and copying, and configure print and copy permissions — all processed locally inside your browser using the PDF-lib engine with zero server uploads.
AES-256 (Advanced Encryption Standard with 256-bit keys) is the strongest symmetric encryption algorithm in widespread use and the global standard for protecting sensitive digital data. It is used by financial institutions, military agencies, and cloud storage providers worldwide. When a PDF is encrypted with AES-256, the document's contents become mathematically unreadable without the correct password — making brute-force attacks computationally infeasible even with modern hardware. The PDF Protector applies AES-256 encryption to your document entirely inside your browser.
A user password (also called the open password) is required to open and view the PDF at all — without it, the document cannot be accessed by anyone. An owner password (also called the permissions password) restricts what an already-opened document allows users to do — such as printing, copying text, or editing content. Setting both passwords gives you the most comprehensive protection: only authorized users can open the file, and their allowed actions within the document are controlled by your permission settings.
Encrypts your PDF using the AES-256 standard — the strongest widely-available encryption algorithm — making the document inaccessible without the correct password.
Set a user password to restrict document opening and an optional separate owner password to restrict editing and copying — providing two independent layers of access control.
Independently toggle print, copy, and edit permissions — choosing exactly what authorized users can do with your document after unlocking it with the correct password.
The encryption engine runs entirely inside your browser using PDF-lib. No files are uploaded to any server — your document and password stay completely private.
If your uploaded PDF is already password protected, the tool detects it immediately and alerts you — preventing confusion and guiding you to use an unlocked version instead.
After encryption, a download link appears immediately — click to save the AES-256 protected PDF directly to your device with the original filename preserved.
Stop sharing unprotected PDFs that anyone can open, copy, or edit. Use the PDF Protector by GrowthSyntax to encrypt your documents with AES-256 password protection and custom permissions — completely free, 100% browser-based, and no sign-up required.