Protect PDF
Add a password to a PDF with real 256-bit AES encryption, so only people with the password can open it. Encryption runs entirely in your browser — the password never leaves your device.
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How to use Protect PDF
- 1
Add your file
Open the Protect PDF tool and drop in your file — or click to browse. Files are read directly into your browser's memory for local processing.
- 2
Adjust the options
Fine-tune the settings to fit your needs. Most tools process locally on your device, so changes preview instantly.
- 3
Download the result
Click the action button and your finished file downloads immediately — no queue, no email, no watermark.
Frequently asked questions
Is Protect PDF free to use?＋
Yes. Protect PDF on AsliPDF is completely free — no account, no daily limits and no watermarks on your output.
Is it safe to use Protect PDF with confidential documents?＋
Yes. Most tools on AsliPDF process your file entirely in your browser using WebAssembly — your document never leaves your device. Some future AI-powered tools may send data to a server with your explicit consent, and will always be clearly labeled.
Do I need to install any software?＋
No. Protect PDF runs in any modern browser on desktop or mobile. There is nothing to download or install, and no sign-up is required.