Add an open-password to any PDF so it cannot be viewed without the correct key. Encryption happens locally in your browser using @cantoo/pdf-lib — your file and password are never sent to any server.
Important: if you forget the password, the file cannot be recovered. There is no reset and no way for us to help — encryption is 100% local.
Drop a PDF or click to browse
Adds an open-password so the file cannot be viewed without it
100% in your browser · Your PDF is never uploaded · No signup
Drop your PDF
Drag and drop any PDF onto the upload area or click to browse. The tool reads the file instantly in your browser — no upload to any server.
Set and confirm a password
Enter a strong password and confirm it. Both fields must match before you can proceed. The password will be required to open the protected file.
Download the protected PDF
Click Protect PDF. Encryption runs locally and the password-protected file downloads to your device as a standard PDF.
Need to compress the file before protecting it? Try PDF Compress first, then protect. See PDF Compress
Sets an open password (user password) on the PDF so that anyone who tries to open the file must enter the correct password. The encryption is applied using @cantoo/pdf-lib entirely inside your browser tab.
Your PDF never leaves your device. Encryption runs locally in JavaScript. We never see your file, your password, or any of its contents. No account is needed.
We are upfront that forgetting the password means permanent loss of access. There is no reset, no backdoor, no way to recover the file. We only show this warning — we do not hide it in fine print.
When you add a password to a PDF, the file's content is encrypted so that any PDF viewer — Acrobat, Preview, Chrome, Edge — will ask for the password before showing the document. This is called a user password or open password. Without the correct key, the encrypted content is unreadable. This tool sets that open password using @cantoo/pdf-lib, a pure-JavaScript fork of pdf-lib that adds encryption support without requiring WebAssembly or any network call.
It depends on whether your file is actually uploaded. Most online PDF tools upload your document to a server, encrypt it there, and then serve it back. That means the service operator sees your file — and your password — even if they claim not to store it. SammaPix runs the entire encryption process inside your browser tab. The file and the password stay on your machine. Nothing is transmitted.
The file cannot be opened or recovered. PDF encryption is designed to be irreversible without the correct key. There is no “forgot password” feature, no backdoor, and no way for us to help — because we never had the password in the first place. This is the honest trade-off of client-side encryption, and we state it clearly before you protect the file.
The @cantoo/pdf-lib library applies the standard PDF encryption scheme (AES-based, compatible with the PDF specification). The result is a standard encrypted PDF that any compliant reader will recognize. The strength of the protection depends on the strength of your chosen password — a short, simple password is much easier to brute-force than a long, random one.