This tool collects your iPhone HEIC photos into a single PDF, with one page per photo. It is the quick way to send photographed documents, receipts, ID pages, homework or a set of pictures as one file that anyone can open and print.
Add your photos, put them in the right order with the arrows in the file list, and check the live page preview. Choose "Fit to photo" for pages shaped exactly like each photo with no borders, or A4 or US Letter with automatic, portrait or landscape orientation and a margin of none, 6, 12 or 20 mm. Each photo is stored in the PDF as JPEG, at full resolution, 2400 px (balanced, still sharp on A4) or 1600 px (small, for email), so the PDF stays a sensible size. JPG and PNG images can be mixed in too.
Limits: this makes an image PDF, so the text in photographed documents is not selectable or searchable (run it through an OCR tool afterwards if you need that). Pages aren't cropped or straightened, so crop photos first if the document edges matter. You can add up to 50 photos per PDF, and photos above about 16.7 megapixels are scaled to that size first.