Protect PDF With Password Encryption Online
Add password protection to your PDF document online for free. Encrypt PDF with user and owner passwords to secure sensitive content.
Drop file here or browse
Maximum file size: 50 MB
Protecting a PDF with a password prevents unauthorized access to sensitive documents — contracts, medical records, financial statements, or any confidential content. CocoPDF encrypts your PDF with AES-256 encryption, creating a password-protected file that only the person with the correct password can open.
The protection goes beyond just a password prompt. The tool sets a user password (required to open the file) and an owner password (required to change permissions). Editing, high-resolution printing, and text copying are disabled — making the protected PDF view-only for users who know the password.
Enter your desired password and click Process. The protected PDF downloads immediately. We never store your password — it is used server-side to encrypt the file and is immediately discarded. The output file is deleted within one hour and no watermarks are added.
How to Protect PDF Online — 3 Simple Steps
- 1
Upload your file
Drag and drop your file onto the upload box, or click to browse. CocoPDF accepts a file up to 50 MB each.
- 2
Adjust the settings
Choose the options you need for Protect PDF. The default settings work well for most documents.
- 3
Download the PDF file
Click the process button. The file is generated on our server and your PDF download starts automatically.
Frequently Asked Questions
What type of encryption is used?
CocoPDF uses AES-256 encryption (PDF 1.7 standard). This is the strongest encryption supported by the PDF format and is resistant to brute-force attacks with a strong password.
What permissions are restricted on protected PDFs?
Protected PDFs allow opening and reading with the correct password. Editing, copying text, and printing at high resolution are restricted. Filling forms and low-resolution printing are allowed.
What happens if I forget the password?
We do not store passwords — they are never sent to our servers in a recoverable form. If you lose the password, use the Unlock PDF tool with another tool that can brute-force simple passwords, or contact a professional PDF recovery service.
Can I protect a PDF that is already password-protected?
The tool requires the input PDF to be unprotected (or you must unlock it first using the Unlock PDF tool). Then you can add a new password.