PDF Password Protect Online — Fast, Secure & Private

Protect your PDF files with password encryption directly in your browser. No uploads, no servers, complete privacy. Your files never leave your device.

Client-Side Only
Instant Processing
Zero Knowledge
100% Private
No Registration
Free Forever
Industry Standard

PDF Password Protect Online Tool

Upload your PDF and protect it with a password — all processing happens locally in your browser

Drop your PDF here or click to browse

Your file will be processed locally — never uploaded to a server

How to PDF Password Protect Online

Secure your PDF files in 3 simple steps

1

Upload Your PDF

Drag and drop your PDF file or click to browse. Your file stays on your device — we never upload it to any server.

2

Set a Strong Password

Enter a secure password to protect your PDF. We use industry-standard AES-256 encryption for maximum security.

3

Download Protected PDF

Download your password-protected PDF instantly. It works with all major PDF readers like Adobe Acrobat.

Why Choose PDF2Locker?

The most secure way to pdf password protect online

Complete Privacy

All encryption happens in your browser. Your PDFs and passwords never leave your device or touch our servers.

Military-Grade Encryption

We use AES-256 encryption, the same standard used by governments and militaries worldwide to protect sensitive data.

Lightning Fast

Process your PDFs instantly without waiting for uploads or downloads. Everything happens locally at maximum speed.

Works Everywhere

Access from any device — desktop, tablet, or mobile. No installation or registration required.

100% Free

Protect unlimited PDFs at no cost. No hidden fees, no premium plans, no watermarks — completely free forever.

Universal Compatibility

Protected PDFs work with all major PDF readers including Adobe Acrobat, Preview, Chrome, and more.

Ready to Protect Your PDF Files?

Start securing your documents with password protection in seconds

Protect PDF Now

Frequently Asked Questions

Everything you need to know about PDF password protection

Is it safe to pdf password protect online using PDF2Locker?

Absolutely! PDF2Locker processes everything locally in your browser using client-side encryption. Your PDF files and passwords never leave your device and are never uploaded to any server. This makes it even safer than traditional online tools that require file uploads.

How does client-side PDF encryption work?

When you upload a PDF and enter a password, our JavaScript code running in your browser applies AES-256 encryption directly to the file. The encrypted PDF is then generated on your device and offered for download. No data is transmitted to any server during this process.

Will the protected PDF work with Adobe Acrobat and other readers?

Yes! The password-protected PDFs created by PDF2Locker use standard PDF encryption that is compatible with all major PDF readers including Adobe Acrobat Reader, Preview (Mac), Chrome PDF viewer, and more.

Is there a file size limit?

Since processing happens in your browser, the limit depends on your device's memory. Most modern devices can easily handle PDFs up to 50-100 MB. For very large files, processing may take longer but will still work.

Do I need to create an account?

No! PDF2Locker is completely free and requires no registration, login, or account creation. Simply visit the site and start protecting your PDFs immediately.

What encryption standard do you use?

PDF2Locker uses AES-256 encryption, which is the industry standard for PDF password protection. This is the same encryption level used by governments and financial institutions worldwide.