Add AES-256 password protection to PDF files free. Set open and edit passwords, control printing and copying permissions. No signup, no watermark.

Adding a password to a PDF takes 30 seconds and protects your document with the same encryption standard used by banks. No software installation, no account required. ## How to Add Password Protection to PDF 1. Go to [pdfhub24.com/protect-pdf](/protect-pdf) 2. Upload your PDF 3. Set an **open password** (required to open the document) 4. Optionally set **permission restrictions** (prevent editing, printing, or copying) 5. Click **Protect PDF** 6. Download your encrypted file ## Choosing a Strong Password The encryption is unbreakable with current computing power — but a weak password defeats the purpose. Use: - Minimum 12 characters - Mixed case letters, numbers, and symbols - Not your name, birthday, or anything guessable Store the password somewhere safe. If you lose it, the file cannot be recovered. ## Open Password vs Permissions Password — Which to Use? **Open password:** Prevents anyone from opening the file without the password. The strongest protection — if someone doesn't have the password, they can't see anything. **Permissions password only:** The file opens without a password, but editing, printing, or copying is restricted. Good for protecting read-only documents from casual modification but not from determined access. **Both:** Maximum protection — requires the open password to view, and a separate password to modify. ## Sharing the Password Securely Never send the password in the same email as the protected document. If the email is intercepted, both arrive together. Instead: - Call the recipient and read the password - Send it via SMS or a messaging app - Use a separate email sent minutes later ## After Protecting — Testing Before sending, test your protected PDF: open it in a standard PDF reader and verify it prompts for the password. Try opening without the password to confirm it's blocked.