QiLing Tools🔒Password Protect PDF - Encrypt a PDF Online
Put an open password on a PDF so nobody can read it without the password. You can also set a separate permissions password that restricts printing, copying text, changing the content and adding annotations. AES-256 is used by default — the only cipher ISO 32000-2 still recommends — and AES-128 is available for older readers. Encryption happens entirely in your browser: neither the file nor the password is uploaded, which beats sending a confidential contract to someone else’s server.
Free · No sign-up · Runs in your browserLast updated:
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How to use Encrypt PDF
- 1Upload a PDF file
- 2Type the open password twice, then set a permissions password and allowed actions if you need them
- 3Click Encrypt & download to get the protected PDF
FAQ
- What is the difference between the two passwords?
- The open password is needed to open the file at all. The permissions password lifts the restrictions, so whoever knows it can print, copy and edit. Leave it empty and it defaults to the open password.
- Can a forgotten password be recovered?
- No. Encryption happens on your machine — we never have your file or your password, and AES-256 cannot be bypassed. Keep the password somewhere safe.
- Can I encrypt a PDF that already has a password?
- Remove the existing password first with our Unlock PDF tool (you will need to know it), then encrypt it again.
- Are my files or data uploaded?
- No. Everything runs locally in your browser with no network upload, and is discarded when you close the page.