Flatten PDF

It merges interactive elements into the page content: form fields, checkboxes, radio buttons, dropdowns, signature fields, comments, highlights, strikethroughs, sticky notes, stamps, and ink marks. The page looks the same afterward, but nothing can be edited, moved, or deleted.

Yes, flattening doesn't turn pages into images. Regular text, images, bookmarks, and page dimensions are untouched; only form fields and annotations become static page content. If you want every page rasterized, use Rasterize PDF instead.

Yes. Flatten the completed form and the values you entered become part of the page, so recipients can't change them. Do it only after you're finished, because there's no way to unflatten a PDF.

That appears when the PDF has annotations but no form fields. It isn't an error; the annotations are still flattened and the file downloads normally.

Comments, highlights, and other markup are burned into the page and stay visible, but they lose their pop-up notes and can't be edited. Links are annotations too, so a clickable link may stop working even though its text remains on the page.

Yes. Upload multiple files and click Flatten PDF; you get flattened_pdfs.zip with one file per PDF. A single file downloads directly with "flattened_" added to the front of its name.

Before. Flatten first so form values and annotations can't be altered, then sign. Flattening rewrites page content, so doing it after a digital signature makes readers report the document as changed.

No. Flattening runs with pdf-lib inside your browser, so the file and whatever you typed into the form stay on your device.