How to password-protect a PDF

Toolsly does not currently offer a PDF encryption or password-protection tool. Its Merge PDF and other document tools do not add passwords or AES encryption. Do not upload a confidential document to a converter just because it claims to be private; choose software whose encryption feature you can verify.

A practical workflow

1. Finish edits in the original document. If several PDFs must be joined, Merge PDF can combine them first, but the merged output is not protected.
2. Open the finished PDF in a PDF editor or document application that explicitly supports password-based PDF encryption. Check that the feature is available in the version you have.
3. Choose a strong, unique opening password and save a new encrypted copy. Keep the unprotected original in a secure location only if you still need it.
4. Close the editor and reopen the saved copy in a separate PDF viewer. Confirm that it asks for the password and that the pages look correct.
5. Share the password through a separate channel from the PDF when the document is sensitive.

An opening password restricts access in viewers that honor PDF encryption. Print or copy permissions are weaker controls and do not prevent screenshots or someone with access to the opened content from copying it. The exact encryption algorithm, compatibility and file-size change depend on the editor and its settings; check the saved file rather than relying on a general benchmark.

The JavaScript library pdf-lib used by some Toolsly document tools is not a password-protection implementation. Its documentation says encrypted documents are unsupported, and its ignoreEncryption option does not decrypt a file. Do not use it as the basis for an AES-256 tutorial. See the pdf-lib encryption documentation.

If you need to turn PDF pages into images for a separate task, use PDF to Images only with a PDF it can open. Image conversion is not a substitute for encryption.