Make background white, or keep it transparent?
Pick white when the image will be shown as it is: a shop listing, a printed sheet, a profile photo. Every viewer and every app sees the same plain backdrop, and JPG, which cannot store transparency, works fine.
Keep it transparent when the picture will be placed on top of something else later, such as a colored banner or a design file. A transparent PNG takes on whatever sits behind it, while a white one always brings its own white rectangle along. If you are unsure, download both: switching Background between White and Transparent here does not redo the cut-out.



















