Nuclear War Simulator is a simulation and visualization tool for exploring large-scale nuclear conflicts, with a particular focus on their humanitarian consequences. It lets users create scenarios involving major powers, assign nuclear weapons individually or use AI assistance, and examine how attacks could affect populations and military targets. A database of contemporary and historical weapons supports scenario building.

Users can design warheads and place them on missiles, aircraft, submarines, silos, and mobile launchers, then deploy forces on a map or import real-world locations from KMZ files. The simulator uses high-resolution population data to estimate the effects of blast, heat, fires, and radiation, including potential fatalities. It also models target destruction and calculates burnt fuel and soot to estimate simplified nuclear-winter effects. Users can place individuals on the map to assess possible injuries and survival, and connect to HYSPLIT for detailed fallout analysis.

The tool supports downloadable and shareable scenarios, unit blueprints, basic customization, and CSV imports and exports for working with other simulation and climate tools.