ONE RESIZER
All-in-One Image & PDF Tools

Password Protect PDF Online Free

Encrypt your PDF documents with custom passwords and permission restrictions — 100% private in your browser.

🛡️ Privacy: Local browser processing for supported tools. Files are not uploaded to our server.
Local Browser Processing
Drop your PDF here to protect with password
or choose a document from your computer or phone
Browse PDF File
Supported: PDF Documents Standard Security Encryption 100% Client-Side Privacy

How to Password Protect PDF Online for Free

  1. Step 1: Upload your PDF — Drag and drop your document into the box or browse from your device.
  2. Step 2: Set Password — Enter your desired password and confirm it. The real-time strength meter helps verify security.
  3. Step 3: Choose Permissions — Customize allowed permissions (printing, copying, annotations).
  4. Step 4: Click Lock PDF — The browser engine encrypts the document streams directly.
  5. Step 5: Download Protected PDF — Save your secure password-protected file with 100% original visual fidelity.

Bank Statements, Payslips & Confidential Proposals Protection

One Resizer provides tools designed to help prepare documents and photos for online submissions and application portals:

Frequently Asked Questions

Yes. One Resizer generates standard PDF Standard Security Handler encryption (/Encrypt dictionary), which prompts for the password in Adobe Acrobat, Google Chrome, Apple Preview, and mobile PDF readers.

No. All encryption algorithms run entirely in your local browser. Your documents and passwords never leave your device.

No. The encryption process encrypts the underlying raw byte streams without converting pages to images, preserving 100% of original visual quality.