The current assessment of cell viability depends on endpoint measurements. Unfortunately, this ignores the levels and rates of in-between measurements. However, advances in technology and image analysis now allow cell viability to be observed more frequently and analysed more quickly. Alternatively, live-cell imaging allows for kinetic monitoring in optimal conditions, helping researchers understand how the cells are reacting over time. Kendra Majewski at CytoSMART Technologies explores how researchers have studied cell viability and how live-cell imaging can provide a better understanding of cell viability.