Convert an Image to an A4-Size PDF

A4, Letter and the rest

The page sizes here are the exact values the PDF format uses: A4 is 595.28 × 841.89 points, US Letter is 612 × 792. Orientation follows the image by default — a landscape photo gets a landscape page — and can be forced either way.

The three fit modes do genuinely different things. Fit inside the page keeps the whole image and leaves white where the shapes disagree. Fill the page scales up until there is no white left, cropping the overflow, which is what you want for a full-bleed page and wrong for a document you need to read every corner of. Stretch distorts the image to the page, and is there for the rare case where you know you want it.

A page with no border at all

Choose Match the image and the page is cut to the picture: no white edge, no letterboxing, no shrinking a screenshot into the middle of an A4 sheet. The resolution selector then decides the page's physical size — the same pixels described as a bigger or smaller sheet of paper. Nothing is resampled by that control; it only changes the units the page is described in.

Very long images are the one place this needs care. A PDF page cannot exceed 200 inches in either direction, so a 20,000-pixel stitched capture at 72 dpi would describe a page the format cannot hold. Instead of producing a file that opens wrong, the resolution is raised automatically until the page fits, and you are told it happened. Not one pixel is changed.

The print resolution you actually get

DPI is not a setting stored inside an image, whatever a print shop's instructions imply. It is arithmetic: pixels divided by printed inches. A 1200 × 1600 photo placed across the full width of A4 prints at about 145 DPI, and no converter setting can make it 300. For a true 300 DPI A4 page you need roughly 2480 × 3508 pixels in the first place.

So every file here reports the DPI it achieves on the page you chose. If the number is too low, your options are a smaller page size, a smaller printed area, or a higher-resolution original — in that order. The full arithmetic is here.

Long images across several pages

A tall scrolling screenshot fitted onto one A4 sheet shrinks to a few per cent of its size and becomes unreadable. Switch Long images to split, and the picture is sliced into page-height bands with a small overlap so no line of text is cut in half. More on when to split and when to use one tall page.