Protect PDF
Add a password (AES-256 encryption). Free — no signup, no watermarks.
How it works
- 1Open your PDF and set a password. Optionally block printing or copying too.
- 2Click Protect. The file is encrypted with AES-256 on your device — your password never leaves your browser.
- 3Download the protected PDF. It now requires the password to open, everywhere.
Common questions
›How strong is the protection?
It's real AES-256 encryption — the same standard used for banking and government documents — not a viewer-level restriction. Without the password, the contents are mathematically unreadable.
›What happens if I forget the password?
The file cannot be opened — by you, by us, by anyone. That's the point of real encryption, so store the password somewhere safe (a password manager) before sharing the file.
›Are the print/copy restrictions absolute?
Opening the file without the password is cryptographically impossible. The print and copy restrictions, however, are honored by well-behaved PDF viewers once the file is open — the PDF standard has no way to make those absolute, and no tool can. The open password is the real security.
›Are my files uploaded to a server?
No. This tool runs entirely in your browser — the file is opened, processed, and saved on your own device. There is no upload in the code path, which you can verify by watching the network tab, or by loading the page and then switching to airplane mode: the tool still works.