Why JPGs are harder to trace than PNGs
JPEG saves space by blurring colours together in small blocks. To the eye that’s invisible, but a tracer sees hundreds of slightly different shades along every edge, and many tools turn each one into its own messy shape.
SVG Harbor first clusters the image into a few main colours and snaps each cluster to the most common real pixel. The noise disappears into the right colour, and the tracer then draws one clean outline per colour.
JPG with a white background?
JPEG can’t store transparency, so logos usually sit on white. Keep Transparent background on and the white is detected and left out, giving you an SVG you can place on any colour.