Password Protect PDF

Adding password protection to a PDF is an act of securing sensitive information. It is counterintuitive, then, that most online PDF encryption tools require you to upload your unprotected document to their server first. For the brief period between upload and encryption, your sensitive file sits unprotected on third-party infrastructure. LocalForge eliminates this contradiction by encrypting your PDF entirely within your browser. The document never travels across a network in its unprotected state.

The encryption engine uses pdf-lib.js to apply AES-256 encryption directly to your PDF structure. You set the password locally, the encryption is computed locally, and the protected file is generated locally. You can configure separate owner and user passwords, and control permissions for printing, copying text, and modifying the document. The processing runs in a Web Worker to maintain performance with large files.

This approach is particularly important for documents that are being encrypted precisely because they contain sensitive information. Tax returns, legal agreements, personnel files, and financial records are exactly the kinds of documents that should never exist unencrypted on a third-party server, even temporarily. With LocalForge, the encryption happens where the document already exists: on your device.

The resulting protected PDF is compatible with all standard PDF readers and uses industry-standard encryption. Your password is never transmitted, stored, or logged anywhere. Apply professional-grade document security without creating the very exposure you are trying to prevent.