Protect PDF

Some documents should not be readable by whoever happens to receive the email. Our free tool to password protect pdf files applies AES-256 encryption — the strongest scheme the PDF format defines, the same one Acrobat uses — entirely inside your browser.

Two passwords do different jobs, and the distinction matters. The user password is required to open the file at all, and it is the one backed by real cryptography. The owner password controls who may change the document's permissions. Setting an owner password with a blank user password produces a file anyone can open but nobody can print or edit, which is often exactly what you want for a distributed report.

Printing, content editing, and text copying are each toggled separately. Worth being straight about how far that goes: permission flags are respected by every mainstream reader but are enforced by the viewer, not by encryption, so a determined user with the right software can work around them. The open password is the part that genuinely protects the file.

Encryption happens on your device and no copy of the password is stored anywhere, which is the whole point — but it also means a forgotten password makes the document permanently unopenable, by us or anyone. Save it somewhere first. If you later need to remove protection from a file you can open, the Unlock PDF tool reverses this.