Protect PDF
Add an open password, AES-256 encryption, an owner password, and document permissions entirely in your browser.
Encrypt a PDF with an open password so only people with the password can view it, using AES-256 encryption via the browser's native Web Crypto API. Also set a separate owner password to control permissions like printing, copying, or editing, and choose RC4 encryption only if you need compatibility with very old PDF readers. Useful before emailing a sensitive document like a contract, financial statement, or HR file. Processing runs entirely in your browser, so the password and PDF never touch a server.
Loading tool
How it works
- 01
Upload your PDF.
- 02
Set an open password and, optionally, an owner password.
- 03
Choose AES-256 or RC4 encryption and set permissions.
- 04
Click Protect and download the encrypted PDF.
Details
- Category
- Documents & PDF
- Formats
- Runs
- In your browser
- Files uploaded
- No
- Cost per run
- Free
- Sign-in
- Not required
- Works offline
- Yes, once loaded
Last updated 2026-08-03
Common questions
Is the password uploaded?
No. Encryption runs locally with the browser Web Crypto API, and the PDF never leaves your device.
Which encryption should I choose?
AES-256 is the secure default for current PDF readers. RC4 is available only for compatibility with older readers.
What is the owner password?
It controls permission changes. If left blank, the document-open password is used for both roles.
What permissions can I restrict?
Common permissions like printing, copying text, and editing can be individually allowed or denied for the encrypted document.