We show that for each scheme that is separated and of finite type over a field, and whose affinization is connected and reduced, there is a universal morphism to some para-abelian variety. The latter are schemes that acquire the structure of an abelian variety after some ground field extension. This extends a classical result of Serre. The proof relies on the corresponding result in the proper case, which was obtained before in a joint work with Bruno Laurent. The open case also relies on Macaulayfication, removal of singularities by alterations, pseudo-rational singularities, and Bockstein maps.