How secure is the PDF password protection?

The tool applies standard PDF encryption methods to protect your document with a password.

Lock PDF

Protect your PDF files with a password. Only users with the password can open the file.

Drop your PDF here

or click to browse

Set a password to protect your PDF document.

Note: Browser-based PDF encryption has limitations. For maximum security, use desktop PDF software.

What Does It Mean to Lock a PDF?

Locking a PDF means protecting a PDF document with a password so only authorized users can open, view, or share it. Password-protected PDFs help prevent unauthorized access to sensitive information such as invoices, contracts, personal documents, and confidential files.

Why Password Protect a PDF?

Protect confidential and sensitive documents
Prevent unauthorized access and data leaks
Secure PDFs before sharing via email or cloud
Comply with privacy and data protection requirements
Maintain full control over document access

How to Lock a PDF Online Securely

Select or drag & drop your PDF file
Enter a strong password for the PDF
Click the lock PDF button
Your PDF is encrypted instantly in the browser
Download the password-protected PDF file

100% Private & Client-Side PDF Locking

Unlike traditional online PDF tools, PngExport locks PDFs entirely inside your browser. Your files are never uploaded, stored, or sent to any server. This ensures complete privacy and makes it ideal for securing sensitive or personal documents.

Common Use Cases for Locking PDFs

Securing legal contracts and agreements
Protecting invoices, reports, and financial data
Sharing confidential business documents
Locking academic certificates and IDs
Sending private PDFs via email or messaging apps

Features of the Lock PDF Tool

Password protect PDF files instantly
No file upload – browser-only processing
Fast and secure PDF encryption
Works on all modern browsers
Free to use with no registration

Benefits of Locking PDFs for Security & Productivity

Locking PDFs helps protect sensitive information while allowing you to share documents confidently. With instant browser-based encryption, you save time, avoid software installation, and ensure maximum data privacy.

Frequently Asked Questions (FAQ)

Is this Lock PDF tool free?

Yes. The Lock PDF tool on PngExport is completely free and does not require signup or installation.

Are my PDF files uploaded to your server?

No. All PDF locking and encryption happens locally in your browser. Your files never leave your device.

How secure is the password protection?

The tool applies standard PDF encryption methods to ensure your document can only be opened with the correct password.

Can I unlock the PDF later?

Yes. You can unlock the PDF anytime using the correct password and a compatible PDF reader.

Does this work on mobile devices?

Yes. The Lock PDF tool works on desktop and mobile browsers that support modern JavaScript.