Protect a PDF with a password
Encrypt a PDF with AES-256, remove a password you already know, or optimise the file losslessly without touching what it shows. The password is passed straight to the encryption engine running in this tab.
Before you upload anything — you will not have to
- Where does my password go?
- Into the encryption engine in this tab, and nowhere else. There is no server here to receive it — which also means nobody, including us, can recover the file if you lose it.
- AES-256 or AES-128?
- AES-256 unless you need to open the file in something very old. Both are real encryption; 128 exists for compatibility with readers that predate the 256-bit standard.
- What does optimising do?
- It rewrites the file's structure — compressing streams, packing objects, linearising for faster first-page display — without changing a single mark on any page.