Career
In 2010, Chang edged out South Africa"s Chad le Clos by 0.18 of a second to claim a gold medal in the 100 m butterfly at the first ever Summer Youth Olympics in Singapore, posting his personal best of 53.13. Chang qualified for the men"s 100 m butterfly at the 2012 Summer Olympics in London, by eclipsing a FINA B-standard entry time of 52.45 seconds. Chang raced to fifth place by a hundredth of a second (001) behind Pini in a time of 52.69 seconds.
Chang failed to advance into the semifinals, as he placed twenty-sixth overall in the preliminary heats.