Protect PDF — Add Password Protection to PDF
Secure your PDF with strong password encryption.
Protect PDF workspace
or drag and drop your PDF here
Files are processed securely in your browser and are never uploaded to our servers.
How to use Protect PDF
Just 3 simple steps to reduce your PDF file size quickly.
- 01→
Select your PDF
Upload the PDF you want to secure.
- 02→
Choose compression
Enter a strong password to lock the document.
- 03
Download instantly
Download your encrypted password-protected PDF.
Why use MyPDF4U for Protect PDF?
No account, no software installation, and no waiting queues. Every tool opens directly to the upload area with zero watermarks and no file count restrictions. Your files are processed locally in client memory, keeping your documents confidential while delivering instant results.
Windows, Mac & Linux
Works in Chrome, Edge, Safari, and Firefox with no software download.
iPhone & Android
Mobile-first design lets you process files directly from photo galleries and Files.
Permanent Metadata
Rotations are written directly into the PDF specification, so it stays fixed forever.
100% Private & Free
Zero server uploads, no subscription walls, and no added watermarks.
Key features
Strong document encryption
Locks viewing access behind password protection.
Client-side security
Your password and file never leave your browser.
Frequently asked questions
How do I add a password to a PDF?
Upload your document, choose your security password, and generate an encrypted copy.
Good to know
PDF open passwords prevent unauthorized access by requiring a key before document contents can be decrypted by any PDF viewer.