Password Protect PDF Online – Encrypt PDF for Free
Lock your PDF with a password in seconds. Set user and owner passwords with AES encryption — all processed locally in your browser. No uploads.
Upload PDF to Protect
Drag & drop or browse files
Supports PDF up to 100MB
Max file size: 100 MB
Guide
How to Use
Upload PDF
Click or drag your PDF file into the upload area.
Set Passwords
Enter a user password (to open) and optional owner password (to restrict editing).
Encrypt & Download
Click 'Protect PDF' and download your password-locked encrypted file.
Benefits
Why Use Our Tool?
AES Encryption
Industry-standard AES encryption compatible with all major PDF readers.
User + Owner Password
Set separate passwords for opening the PDF and for restricting editing.
No Uploads
Encryption happens 100% in your browser. Files stay private on your device.
Instant Download
Protected PDF is ready to download in seconds.
FAQ
Frequently Asked Questions
What type of encryption is used?
AES encryption via jsPDF — compatible with Adobe Acrobat, Preview, Chrome, Edge, and all major PDF viewers.
What is the difference between user and owner password?
The user password is required to open the PDF. The owner password controls editing, printing, and copying permissions.
What restrictions are added to the PDF?
Viewers can open and read the PDF with the user password. Copying text, editing, and printing can be restricted via the owner password.
Can I recover the password if I forget it?
No. The password is never stored anywhere (processing is entirely client-side). Keep your password safe — there is no recovery option.
Is this compatible with all PDF readers?
Yes — standard AES-encrypted PDFs work in Adobe Reader, Preview, Chrome, Edge, and more.
Will the file content change?
No. Only security settings are added. The text, images, and layout of your PDF remain exactly the same.