The competition exists out of three rounds, each with races of up to nine athletes. In the first round, the sixteen fastest athletes qualify for the semifinals. In the semifinals, the two fastest athletes of each race, as well as the four fastest non-qualifiers advance to the final. The fastest competitor in the final is the winner of the event.
Preview[]
Twenty-seven athletes qualified for the event with defending Olympic champion and world champion Katinka Hosszu as the name to beat for gold. The Hungarian won gold at the previous four editions of the world championships and had recorded the fastest time of the qualification period. Sydney Pickrem took bronze at the most recent world championships and would be one of the main medal contenders, with 2017 silver medalist Yui Ohashi, and Alex Walsh also still within reach. Other medal contenders and potential outsiders also included European champion Anastasia Gorbenko, silver medalist at the European championships Abbie Wood, Kate Douglass, and Miho Teramura.
