Protect PDF
Add a password and AES-256 encryption to your PDF.
Processed on your device – your files are not uploaded.
1. Choose unencrypted PDF
Drop your PDF here
or choose a file from your device
PDF • up to 100 MBBefore you start
- Files
- Limits
- 1 file, up to 100 MB
- You get
- One PDF document encrypted with AES-256 and protected by your chosen password.
2. Set password
Keep the password safe. If you forget it, nobody can open the file – we never see or store it.
3. PDF protected
How it works
- Choose your PDF. Drop or select an unencrypted PDF up to 100 MB.
- Set a password. Type and confirm a password with at least 6 characters.
- Protect and download. The tool encrypts the PDF with AES-256 and saves your protected file.
Limits
- Single open password: Protects the PDF with a password required to open it. It does not configure separate permissions for printing or copying.
- Unencrypted files only: If the PDF already has a password, unlock it first using Unlock PDF before setting a new password.
- Keep your password safe: If you forget the password, nobody can open the file. We never see, store, or log your password.
- File size up to 100 MB: Processed locally in your browser.
Check it yourself: your file is not uploaded
- Choose your PDF file on this page.
- Turn off Wi-Fi or mobile data.
- The tool still encrypts your PDF and saves the result because all encryption occurs entirely within your browser.
On a computer, press F12 to inspect Network activity and confirm no request transmits your PDF or password.
Encrypt and password-protect PDFs on your device
Protect PDF adds a password to a PDF that does not have one yet, before you share or store it. It encrypts the file with AES-256.
All encryption takes place locally in your web browser. Your file and password are never sent to a server. Keep your password safe: because we never see or store it, nobody can recover the file if the password is lost.
Frequently Asked Questions
What type of encryption does Protect PDF use?
The tool encrypts your PDF with 256-bit AES encryption (AES-256). Any recipient must enter the exact password you set to open and view the document.
Can you recover my file if I forget the password?
No. We never see, transmit, or store your password or file. If you forget the password, nobody can open or recover the document.
Can I set separate printing or editing permissions?
No. Protect PDF sets a single password required to open and read the file. It does not configure separate permissions for printing or copying.
Can I protect a PDF that already has a password?
No. If the PDF is already password-protected, you must unlock it first using Unlock PDF, and then protect it with a new password.