Free PDF Password Protector
Lock your PDF with a password before sharing sensitive documents. Set a user password (required to open the document) and optionally an owner password (controls editing and printing permissions). Uses standard 128-bit RC4 PDF encryption — the output opens in any PDF viewer including Adobe Acrobat, Preview, and Chrome. Everything happens in your browser.
Drop a PDF here or click to browse
Your file never leaves your device
🔒 Your files never leave your device — all processing happens in your browser.
Frequently Asked Questions
Are my PDF files uploaded to a server?+
No. All encryption is performed inside your browser using a JavaScript implementation of the PDF standard security handler. Your document never leaves your device.
What is the difference between a user password and an owner password?+
The user password (also called the open password) is required to open the PDF in any viewer. The owner password controls permissions — it unlocks editing, printing, and copying if a reader enters it. You can set both, or just the user password for simple open protection.
What encryption strength is used?+
This tool uses 128-bit RC4 encryption, the standard security handler used in PDF 1.4 and later. It is recognized and enforced by all major PDF viewers including Adobe Acrobat, macOS Preview, Chrome, and Edge.
What if I forget the password?+
There is no recovery option. PDF encryption is designed so that the password cannot be recovered without the original key. Store your password in a password manager before protecting the document.
Can I restrict printing and editing without a user password?+
Yes. You can set only an owner password (leave the user password blank) to allow anyone to open the PDF but prevent them from editing, printing, or copying content. However, note that permission restrictions are advisory — some PDF tools may ignore them.
Will the password-protected PDF work in all viewers?+
Yes. The output uses the standard PDF encryption format (PDF 1.4 security handler, revision 3) which is supported by every major PDF viewer on all platforms.
When to Password-Protect a PDF
Password-protecting a PDF is appropriate whenever the document contains information that should only be accessible to specific recipients — invoices with payment details, contracts before signing, personnel files, tax documents, or any file shared over email where you cannot guarantee the inbox is private.
User Password vs. Owner Password
PDF supports two distinct passwords. The user password (also called the open password) must be entered before the document can be viewed at all. The owner password unlocks permissions — if set, it allows the holder to print, copy text, and edit the document. A document can have one or both passwords set.
Common setups: set only a user password to prevent unauthorized access; set only an owner password to allow anyone to read the file but prevent printing or copying; set both for full control over both access and permissions.
Encrypting Invoices Before Sending
If you use the Invoice Generator to create client invoices, consider running the downloaded PDF through this password protector before sending it by email. Share the password with the client through a separate channel (SMS or a password manager share link) for a simple but effective security layer.
The Importance of Saving Your Password
PDF encryption is designed to be irreversible without the password. There is no "forgot password" option. Store the password in a password manager (1Password, Bitwarden, LastPass) immediately after setting it, and do not rely on memory alone for documents you may need weeks or months later.
Privacy — Your Files Never Leave Your Device
The encryption is performed entirely in your browser using a JavaScript implementation of the PDF standard security handler. Your document — and your password — are never transmitted anywhere. Unlike cloud services that process your PDF on their servers, there is no third party that ever sees your document content or your chosen password.