The heights almost never match
Two photographs from the same phone, taken minutes apart, are usually the same size. Two photographs from anywhere else — a screenshot and a camera roll picture, a scan and a snap, one cropped and one not — almost never are. Joining them horizontally means deciding what to do about it, and there is no answer that is right every time.
- Match the biggest grows the smaller photograph until the heights agree. Nothing is lost from the larger one, and the smaller one is a little softer than it was.
- Match the smallest shrinks the larger one instead. Everything stays sharp; the result is smaller than the best picture you put in.
- Match the first lets whichever photograph is on the left set the rule. Useful when one of the two is the one that matters.
- Leave them alone scales nothing and fills the space beside the shorter photograph with whatever ground colour you picked. Both pictures come out untouched, and the join has a visible band in it — which is often exactly what you want.
Where the spare space goes
As soon as you stop scaling, the shorter photograph has room above and below it, and you get to say which end it sits at. Top, middle or bottom — middle is the safe choice for a pair of portraits, bottom is usually right when both pictures have a horizon or a table edge you want to run straight across the join.
Saving it, and what the numbers mean
The size shown under the preview is the size of the file you are about to save, not the size of the drawing on screen. Forms and printers ask for that number and it is worth reading before you press the button. PNG keeps every pixel exactly and is the right choice for anything with text in it; JPEG is much smaller and fine for two photographs; WebP is smaller than PNG and still keeps a see-through ground.
One thing this page will not do: chase a file size. It tells you the exact pixel dimensions and a rough weight, and stops there rather than quietly degrading your photographs. If a form has told you the result must come in between two kilobyte figures — a photo and a signature for an application — the photo and signature page is built for exactly that.
Questions people ask about a pair
One photo is portrait and the other is landscape. Can they still go side by side?
They can, and the result is wide and short. Matching the tallest turns the landscape picture into a very wide one alongside the portrait; matching the shortest cuts the portrait down to the landscape's height. If neither looks right, scale nothing and let the ground colour fill the space above and below the shorter picture — that keeps both photographs exactly as they were shot.
Which photo ends up on the left?
Whichever is first in the tray. Filename order decides that to begin with; one click reverses it, and dragging a thumbnail — or holding Alt and pressing an arrow — moves it wherever you want.
Will joining two photographs make them worse?
Only where something had to be scaled, and the panel tells you when that happens. A picture made bigger than it was taken is softer, because the extra pixels are guesses; a picture made smaller loses fine detail. Scaling here steps down in halves with a careful last pass, which is what keeps text and edges from going ragged, but the way to lose nothing at all is to scale nothing at all.
Can I put a white strip between the two photographs?
Yes — set the gutter to the number of pixels you want and pick white as the ground. The gutter is the gap between them and the margin is the border around the outside; both are zero unless you say otherwise.