The Fit image option creates each PDF page around the image itself, which is helpful when you want to preserve the original aspect ratio and avoid forcing every page into the same paper size. A4 creates standard document pages and is better for files that may be printed, submitted, or stored with other office documents.
Orientation applies when A4 is selected. Choose Portrait for vertical documents, forms, and phone screenshots, or Landscape for wide images, charts, presentation captures, and horizontal photos. Margins can be set to None, Small, or Large. None gives the image the most space, while Small or Large adds white space around the image for a more document-like layout.
Compression controls the image data written into the PDF. No compression keeps the image closer to the original visual quality. Low, Medium, and High compression can reduce file size when the PDF needs to fit an upload limit or be sent through email. Higher compression usually creates smaller PDFs, but very detailed photos may lose more visible detail.