Laboratory testing of fluid catalytic cracking (FCC) for feeds and catalysts in a confined fluid bed reactor (CFBR) is widely applied in industry as a standard evaluation tool. In this paper, comparative yields are presented from a circulating riser reactor (CRR) in an FCC pilot plant and in a standard CFBR unit. It is shown that, although a good agreement is obtained for comparative ranking of feedstock quality and catalyst activity, there are significant differences on the absolute yields obtained at constant conversion. These results are explained by differences in reactor operating parameters and their effect on catalyst performance and product selectivity. (C) 2014 Elsevier B.V. All rights reserved.