Add military-grade AES-256 encryption to any PDF file directly in your browser. No uploads, no servers, no privacy risks β just pure, secure, client-side protection.
Upload your PDF, set a strong password, and download your encrypted file in seconds. Everything happens locally in your browser.
Client-Side AES-256 Encryption β No file uploads required
Supports PDF files up to 100MB
Your password-protected PDF is ready to download. The file was encrypted entirely in your browser.
β¬οΈ Download Protected PDFThree simple steps to password protect your PDF online. No account needed, no learning curve.
Drag and drop your PDF file into the upload zone or click to browse. Your file is read directly by your browser β never sent to any server.
Enter a strong password for your PDF. Use our real-time strength meter to ensure your password is secure enough to protect your sensitive documents.
Click encrypt and your browser instantly applies AES-256 encryption. Download the protected PDF file β it's ready to share securely.
PDFLocker is packed with powerful features to keep your documents safe and secure.
Industry-standard AES-256 encryption protects your PDF with the same security used by governments and banks worldwide.
Your files are processed entirely within your browser using the Web Crypto API. Nothing is ever sent to our servers.
Choose exactly what recipients can do with your PDF β restrict printing, copying, editing, or annotations independently.
Encrypt PDFs in under 2 seconds. No waiting, no queues, no loading bars β just instant protection every time.
Works seamlessly on all devices β iPhone, Android, tablets, and desktops. PDF password protect online anywhere, anytime.
Unlike other online PDF tools, PDFLocker processes everything locally in your browser β here's why that matters.
Your confidential documents, financial reports, legal contracts, and private files never leave your device. Zero exposure to third parties.
Since there's no server upload, large PDFs process as fast as small ones. No file size restrictions, no upload bandwidth bottlenecks.
Once the page is loaded, the tool works without an internet connection. Protect your PDFs even on planes, in remote areas, or offline environments.
Since no data is transmitted, PDFLocker is inherently compliant with strict data protection regulations like GDPR, HIPAA, and CCPA.
No subscriptions, no premium tiers, no watermarks. PDF password protect online for free, forever. No catch, no signup required.
No registration, no email verification, no personal data collection. Use the tool instantly and anonymously, any time you need it.
PDFLocker was designed with security and user privacy as the top priority. Here's what makes us different.
Built on the open-source pdf-lib library. Transparent, auditable code that the security community trusts.
We don't track what files you process, how you use the tool, or collect any personally identifiable information.
Your PDF bytes never travel over the network. Verified by browser developer tools β no upload requests are made.
Generates PDF 2.0 compatible encrypted files that work with Adobe Acrobat, Preview, and all major PDF readers.
Join thousands of professionals who trust PDFLocker to protect their sensitive documents. No signup, no cost, no compromises.
π PDF Password Protect Online β Start Now