This data is associated with the paper entitled “Performance-based seismic design optimization of steel frames under system and component constraints using the improved water strider algorithm”. Four algorithms consisting of IWSA (improved water strider algorithm), WSA (water strider algorithm), PSO (particle swarm optimization) and ECBO (enhanced colliding bodies optimization) are utilized for carrying out the optimization. The algorithms have been run multiple times for each structure to provide meaningful statistical results such as mean value and standard deviation. For the 6-storey frame, each algorithm has been run 10 times independently, and for the 12-storey frame 6 independent runs were carried out. The results of the algorithms are provided in this repository. Frame6 and Frame12 include the data for the 6-storey and 12-storey frame, respectively.