JPEG saves space by discarding detail. Zoom into a logo copied from a website and you'll find stepped edges, muddy corners and faint colour halos wherever two colours meet.
Online converters trace all of that, so the vector keeps every blemish. We look past the compression to the shape the logo is meant to be, and draw that with clean paths and flat colour.
For colour separations, cutter-ready paths and the full service, see our vector conversion service.
No need to chase the original designer. Send the biggest version you have; we redraw from what's visible and check anything unclear with you.