Protect PDF
Password-protect a PDF with strong encryption so it can only be opened with the password. Runs entirely in your browser using deterministic PDF encryption; your file and password are never uploaded.
Runs in your browserDon't take our word for it
Open your browser's Network tab and watch: your file never leaves this page. Or load this tool, turn off your internet, and it still works.
Drop files, paste, or click to browse
Files are processed in your browser — they never leave your device.
Add a file to continue.
How to protect pdf
Password-protect a PDF with strong encryption so it can only be opened with the password. Runs entirely in your browser using deterministic PDF encryption; your file and password are never uploaded. To use Protect PDF: 1) add your file by dragging them in or clicking to browse, 2) set your security options, 3) download your result — done in seconds. It's free, needs no signup, and most tools run right in your browser so your files never leave your device.
Frequently asked questions
- Is Protect PDF free to use?
- Yes. Protect PDF is free to use. It's free, needs no signup, and most tools run right in your browser so your files never leave your device.
- Are my files safe and private?
- Completely. Protect PDF processes your file directly in your browser, so it is never uploaded to any server.
- Do I need to install anything?
- No. Protect PDF works in any modern web browser on Windows, Mac, Linux, iPhone and Android — nothing to install.