In 2015 Visser became Dutch senior champion for the first time, winning the 60 m hurdles in 8.12 at the national indoor championships in Apeldoorn; she was selected for the European Indoor Championships in Prague, despite not quite meeting the national federation's qualification standard. In Prague she qualified from the heats on time, but fell in her semi-final and was eliminated. Outdoors, Visser improved her national under-23 hurdles record to 12.97 (+1.4) at the FBK Games in Hengelo on May 24; the following week, she placed 5th in the Hypo-Meeting with a personal best 6467 points. Before the 2015 European U23 Championships in Tallinn Visser had reached the qualifying standard in five events (100 m, 200 m, 100 m hurdles, long jump and heptathlon); she chose to compete in the hurdles and the long jump, winning a bronze in the hurdles with a time of 13.01 (-0.2).