The €37m extension includes new stations at Parc Malraux, Cour de l'Illiade, and Graffenstaden, offering a 28-minute journey time between Graffenstaden and the city's main railway station.
Services operate at 4-7 minute intervals at peak times and every 7-10 minutes at other times.
Line E services were also extended south to Campus Ilkirch station on April 23.
