Protect PDF with Password
Add 256-bit AES password protection to an unencrypted PDF. Free to use. Files are processed locally in your browser.
256-bit AES encryption. Your file and password are processed locally in your browser.
Drop your PDF here or click to browse
or click the button below to browse your files
💡 At least 4 characters are required. Keep the password; PDFcraft cannot recover it.
Add an opening password with qpdf
Encryption and permissions
Protect passes an unencrypted PDF to qpdf WebAssembly with 256-bit AES encryption. It uses the entered password as both user and owner password and permits full printing and content extraction. It does not offer separate owner-password or permission controls.
The two password entries must match and contain at least four characters. That minimum is an input rule, not a strength guarantee: encryption does not make a weak password hard to guess. Save the password securely and verify the recipient's access and delivery requirements.
Check access, not just the success message
The wrapper checks qpdf's exit status and requires a nonempty output. Damaged, unsupported or already-protected inputs can fail. If the security engine cannot load, check connectivity and browser restrictions before retrying.
Controlled Node tests reopened the encrypted fixture with the known password and rejected missing/wrong passwords; extracted text and observed field values were checked. This does not establish form interaction, signature preservation or universal security. Password protection does not replace careful distribution.
Where the file and password are used
The file and password are supplied to the local qpdf runtime, not a PDF-processing upload service. Its WASM engine loads from jsDelivr. Temporary input/output files are removed from the runtime filesystem and the input byte buffer is cleared afterward; that is not a guarantee of secure erasure from all browser memory.