Lock a PDF with a password so only people who know it can open the file. ConvertOwl applies standard PDF encryption entirely in your browser, which means both the document and the password you type stay on your device and are never uploaded. It's a genuinely private way to secure sensitive files before sharing them.
Add your PDF
Drop the PDF you want to secure onto the page, or click to browse. Files up to 100 MB are supported and handled locally.
Choose a password
Type a password, then re-enter it to confirm. Pick something strong and memorable — anyone opening the file will need to type it.
Protect the PDF
Click Protect PDF. Your browser encrypts the document with a standard PDF password using the key you provided.
Download the protected file
Save the encrypted PDF. From now on, opening it in any viewer will prompt for the password you set.
No. Encryption happens entirely in your browser, so neither your PDF nor the password you type is ever transmitted or stored on a server. This is a real security advantage over online tools that receive your unprotected file and your password on their servers.
The tool applies standard PDF encryption, the same password-protection mechanism built into the PDF specification and understood by Acrobat, Preview, Chrome, and other viewers. When someone opens the file, their PDF reader prompts for the password before showing any content.
There is no recovery. Because encryption is standard and we never see your file or password, we cannot reset or bypass it — and neither can anyone else. Store the password somewhere safe; without it, the PDF genuinely cannot be opened.
Yes. It uses standard PDF encryption, so any compliant reader on Windows, macOS, iOS, Android, or the web will recognize it and ask for the password. Recipients don't need any special software beyond a normal PDF viewer.
Yes, as long as you know it. Use the Unlock PDF tool and enter the correct password to produce an unprotected copy. Both protecting and unlocking run locally in your browser, so your document stays private throughout.
No. Encryption wraps the existing file without altering its pages — text, images, and layout are exactly as before. The only change is that a password is now required to open it; the content itself is untouched and loses no quality.
Something not working? Report a bug
