Add a password to any PDF for free. All encryption happens locally — your file never leaves your device.
Or click to browse · Single PDF file
✅ PDF locked successfully!
Professional-grade PDF encryption right in your browser.
Passwords are applied using AES-128/256 encryption through pdf-lib, the same standard used by professional PDF tools.
Your PDF and password never leave your device. All operations are 100% client-side for maximum privacy.
Choose exactly what viewers can do — printing, copying, editing, and annotations can all be individually controlled.
No signup, no limits, no waiting. Lock any PDF with a password in seconds, completely free.
Drag and drop your PDF or click to browse and select the file you want to protect.
Enter a strong password and choose optional permission settings like printing and copying.
Click "Lock PDF" and instantly download your password-protected PDF file.
Adding a password to a PDF prevents unauthorized access and protects sensitive information. Whether you are sharing a confidential report, a signed contract, or private financial data, our free PDF locker adds AES encryption directly in your browser.
Combine uppercase letters, numbers, and symbols for maximum security. Avoid simple words or birthdates.
Once locked, a PDF cannot be opened without the correct password. Store it in a password manager or secure notes.
Always lock your PDF before sending via email or cloud storage to ensure only the intended recipient can open it.
User passwords restrict opening. Owner passwords restrict editing and printing. Set both for maximum control.
PDF password protection uses AES-128 or AES-256 encryption depending on the PDF version. Our tool implements the PDF encryption specification directly in the browser using PDF-lib.js, meaning your document content is encrypted before it ever reaches a download. This ensures that even if someone intercepts the file during transfer, they cannot access its contents without the password you set.