🔒 Flatten PDF

Flatten it. Flattening draws the field values into the page itself and removes the editable fields, so the content is fixed. This is different from password protection, which restricts opening or printing but leaves the fields editable.

A PDF keeps form fields and comments as separate interactive layers sitting above the page. Flattening merges them into the page itself, so what you see becomes the actual page content. The document looks identical but can no longer be edited, and it renders the same in every viewer.

Some viewers fill in form fields without saving proper appearance streams, so other programs show the fields blank. Flattening writes the values into the page content, which fixes the problem permanently.

It does not have to. Many tools flatten by converting each page to a picture, which bloats the file and destroys searchable text and screen-reader access. This tool rewrites the document structure instead, so text stays text and vector graphics stay sharp.