OptiDrop

Password Protect PDF — Free Online Tool

Add password protection to your PDF files. Set user and owner passwords, restrict printing, copying, and editing. Everything runs in your browser — your files never leave your device.

Drop a PDF File Here or Tap to Browse

Supports PDF files up to 100MB

No upload — your PDF stays on your device.
100% Local — your file never leaves this device

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Password Protect PDF Files Online — Free, No Upload Required

OptiDrop's PDF Password Protector is a free online tool that adds password protection and permission restrictions to your PDF documents. Whether you need to secure a confidential contract, protect financial records, or prevent unauthorized copying of your work, our tool handles it all. Unlike other online services, OptiDrop processes everything locally in your browser — your PDFs are never uploaded to any server, making it completely safe for sensitive documents.

Two Types of PDF Passwords

A user password (also called an open password) is required to open and view the PDF. Without it, the document cannot be read at all. An owner password controls what actions are permitted — such as printing, copying text, or modifying content. You can use one or both passwords depending on your security needs.

Permission Restrictions

Beyond passwords, you can set specific permission restrictions. Prevent printing to stop physical copies, disable copying to block text and image extraction, or restrict modifications to keep your document's content intact. These restrictions are enforced by compliant PDF readers like Adobe Acrobat, Foxit, and most modern browsers.

100% Private — No Upload Required

Your PDF never leaves your device. All encryption happens locally using the pdf-lib JavaScript library running in your browser. No data is transmitted to any server. This makes our tool ideal for protecting confidential business documents, legal contracts, financial statements, and personal files without any privacy concerns.

Frequently Asked Questions

A user password (also called the open password) is required to open and view the PDF document. Without it, the file cannot be read at all. An owner password controls what actions are allowed — such as printing, copying text, or modifying content. A PDF can have one or both passwords set independently.
Absolutely. This tool runs entirely in your browser using client-side JavaScript. Your PDF file is never uploaded to any server. The encryption happens locally on your device, making it completely safe for confidential documents like contracts, financial records, and personal files.
Yes. You can add only an owner password and set printing/copying restrictions without requiring a user password. In this case, anyone can open and view the PDF, but the restrictions you set (such as no printing or no copying) will still be enforced by compliant PDF readers.
This tool uses 128-bit RC4 encryption via the pdf-lib library, which is the standard encryption supported by all PDF readers. While it provides solid protection for most use cases, highly sensitive documents may benefit from AES-256 encryption available in dedicated desktop software. The strength of your password also plays a critical role — use a mix of uppercase, lowercase, numbers, and symbols for best security.

Last updated: June 2026