Flatten every page to an image so nothing stays editable
When a document must render identically everywhere regardless of fonts, when you are sending a file that should not be easy to re-edit, or when a PDF renders differently in different readers because of unusual fonts or transparency.
No, and it is important not to confuse them. Rasterizing removes the text LAYER, but anything visible on the page is still visible in the image. To remove sensitive content, use Redact PDF, which deletes it.
Usually bigger for text documents, because sharp text is expensive to store as pixels. Lower the DPI or use JPEG if size matters. Scans often get smaller.
Selectable text, search, links, form fields, annotations and any structure tags. Choose PNG for line art and screenshots; JPEG is smaller for scans and photos.
