Mannheim’s *KatRetter* App Saves Lives with 700+ First Watch Volunteers
A year after its launch, Mannheim’s KatRetter app has built a strong network of emergency responders. The smartphone-based system alerts registered first watch users when someone nearby suffers a cardiac arrest. So far, 701 users have signed up to provide critical help before paramedics arrive.
The app was introduced in Mannheim in late 2024 to speed up emergency response. When a cardiac arrest occurs, it notifies trained volunteers in the area at the same time as emergency services. Over the past year, alerts were sent out 328 times, with responders accepting 47 percent of them.
Response rates have steadily improved. In the first half of 2025, only 35 percent of alerts were answered. By the second half, this figure rose to 57 percent. A key factor in the system’s success is the high level of medical training among users—78 percent hold qualifications beyond the basic requirements. The project has also expanded beyond Mannheim. The Rhine-Neckar metropolitan region, including Ludwigshafen, signed a cooperation agreement to standardise KatRetter alerts across all participating districts. Meanwhile, Hameln-Pyrmont district activated the app on 10 December 2025. In Regensburg, the system will continue from 1 January 2026 under a new name, Region der Lebensretter, requiring current responders to re-register. To strengthen coverage, cross-regional notifications have been introduced. This allows responders from nearby areas to be called in when local help is scarce.
The KatRetter network in Mannheim now includes 701 trained volunteers. With growing participation and improved response rates, the system aims to expand further across Germany. The focus remains on increasing the number of first responders to save more lives in emergencies.
