Lock PDF with Password
Lock any PDF file with a password. Free browser-based PDF encryption tool.
Lock PDF with Password is a free online tool that secures your PDF documents with password protection and permission restrictions. Set an owner password to prevent printing, copying text, or editing, and optionally set an open password that users must enter to view the document. You can choose from granular permissions: allow or deny printing, copying content, modifying text, adding annotations, and filling forms. The tool uses industry-standard AES-256 encryption to ensure your document is truly protected. All processing happens locally in your browser — your PDF is never uploaded to any server, so your content and password remain completely private. There is no file size limit, no sign-up, and no watermark added to the output. It is ideal for protecting confidential business reports, securing legal contracts before sharing, restricting access to sensitive academic papers, preventing unauthorized printing of ebooks, or adding a layer of security to any PDF document. Works on all modern browsers across desktop and mobile devices.
What is the difference between owner and user passwords? +
With Lock PDF with Password, A user password is needed to open the PDF. An owner password restricts actions like printing, copying, or editing — even if the file is openable.
What encryption strength does the tool use? +
The tool uses AES-256 encryption, which is the current industry standard for PDF security.
Can I set different permissions for different actions? +
Yes. You can independently allow or deny printing, text copying, content editing, annotation adding, and form filling.
Will protecting a PDF change its content or quality? +
No. Encryption is applied to the existing content without altering text, images, layout, or any visual elements.