Turn a 9:16 photo into 16:9

A phone shoots one shape and most screens want the other, which is why this conversion keeps coming up — and it is the one where the difference between adding and cutting is most obvious. A 16:9 frame is nearly twice as wide as it is tall; your photo is nearly twice as tall as it is wide. There is no arrangement of those two facts in which cropping leaves you much of a picture.

So the height stays exactly as it was and the width grows around it. Your subject keeps their feet and the top of their head, at the full resolution the camera recorded, and what appears either side is built from the photograph's own edges. The page opens with a blurred cover because that is what two thirds of a frame can carry without drawing attention to itself.

The target is already 16:9 when you arrive, so the moment a photograph opens the canvas is measured and the fill is painted. Change the fill with a single key — B for the blur, M for a mirror, C for one flat colour — and the canvas repaints against a reduced copy so it keeps up while you decide.

When you save, the same painting routine runs again at the real size. That is worth saying plainly because it is where tools like this usually go wrong: a preview drawn by one piece of code and an export drawn by another will eventually disagree, and the disagreement always turns up in the file rather than on the screen. Here there is one routine and it does not know which of the two it is drawing.

What exactly are the numbers behind this conversion?

A 1080 by 1920 photo — the ordinary shape a phone shoots in portrait — needs to be 3,413 wide to be 16:9 at that height. So 2,333 columns arrive, split evenly at 1,166 on the left and 1,167 on the right when the anchor is centred. Sixty-eight percent of the finished picture is therefore material this page built. That is a lot, and it is why the blur is the default: a soft backdrop carries two thirds of a frame far better than a hard-edged one does.

Could you not just add black bars instead?

You can, and it takes two clicks: choose One colour, then the near-black swatch. It is the honest option for video stills and the safest one for anything going onto a dark page. The reason it is not the default is that a black band either side of a bright photo reads as a mistake on a white feed, whereas a blurred continuation of the same picture reads as a deliberate frame. Both are one click apart, so pick by where the file is going.

My subject is standing right at the edge and the mirror gave them two heads.

That is the failure mode mirroring has, and nothing about the seam slider will fix it — a reflection puts an exact copy of whatever touches the join immediately beside it. Two ways out. Nudge the photograph sideways with the arrow keys until the subject sits well away from the edge, or move to the blurred fill, where the same person appears only as an out-of-focus shape at a completely different scale. On a portrait of a person, blur is almost always the right call.

Will this work for a YouTube thumbnail?

It gives you the right proportion, which is the hard part. A thumbnail wants 16:9 and yours is now 16:9, with the subject at full resolution in the middle rather than cropped to a slice of itself. What this page does not do is anything else a thumbnail needs — no text, no outline, no brightening. It hands you a correctly shaped picture and stops there.