PROBLEM TO BE SOLVED: To provide humanization of rabbit antibodies using universal antibody framework.SOLUTION: The invention relates to a universal antibody acceptor framework and to methods for grafting non-human antibodies, e.g., rabbit antibodies, using the universal antibody acceptor framework. The antibodies produced by the method of the invention is useful for various diagnostic and therapeutic applications. The invention provides methods for grafting rabbit and other non-human CDRs, into the soluble and stable light chain and/or heavy chain human antibody framework sequences disclosed herein, thereby generating humanized antibodies with superior biophysical properties. In particular, immunobinders generated by the methods of the invention exhibit superior functional properties such as solubility and stability.