100% free tool
Protect PDF
Add an AES-256 password to a PDF, in your browser.
- No sign-up required
- Instant results
- Nothing is uploaded
or drop them here
Frequently asked questions
Common questions about the protect pdf.
What happens if I forget the password?+
The document is unrecoverable. There is no backdoor and nobody - including us - can open it for you. Keep an unprotected copy somewhere safe before you send the protected one out.
How strong is the protection?+
It uses AES-256, the strongest option in the PDF specification. The real limit is your password: a short or guessable one can be attacked offline, so use a long passphrase for anything that matters.
Are the permission tick boxes enforced?+
They are honoured by readers that follow the specification, which covers ordinary use. They are a statement of intent rather than a lock - a determined user with the password can work around them. The password itself is the part that genuinely protects the file.