Protect PDF with a password
Add a password so the PDF cannot be opened without it.
Add a PDF and choose a password. The file is encrypted inside your browser and cannot be opened without that password. Neither the document nor the password is sent anywhere.
How to use it
- Add the PDF you want to protect.
- Choose a password and type it twice.
- Press Protect PDF and download the encrypted file.
Why use this tool
Completely private
Everything runs inside your browser. Your files and text are never sent to a server.
Free, with no limits
No sign-up, no watermarks and no cap on how many times you can use it.
Instant results
There is no upload or queue to wait for, so results appear as fast as your device can work.
Works on any device
Runs in any modern browser on phone, tablet or desktop. Nothing to install.
Frequently asked questions
- Is my password sent to a server?
- No, and this is the whole point. Encryption runs in your browser, so the password exists only on your device. Online tools that do this server-side necessarily receive both your document and your password — which is a strange trade for a file you are trying to keep private.
- Can the password be recovered?
- No. The document is genuinely encrypted, so there is no reset and no back door. If you forget the password the file is unreadable. Store it somewhere before you close the tab.
- How strong is the encryption?
- It uses the PDF standard's own encryption, which every reader understands. Its real strength depends on your password — a short or common one can be attacked offline. Use something long, and consider the password generator on this site.
- Will it open in any PDF reader?
- Yes. It is standard PDF encryption, so Acrobat, browsers, phones and printers all prompt for the password normally.