Flightradar24 is a Swedish Internet-based service that shows real-time aircraft flight tracking information on a map. It includes flight tracking information, origins and destinations, flight numbers, aircraft types, positions, altitudes, headings and speeds. It can also show time-lapse replays of previous tracks and historical flight data by airline, aircraft, aircraft type, area, or airport. It aggregates data from multiple sources, but, outside of the United States, mostly from crowdsourced information gathered by volunteers with ADS-B receivers and from satellite-based ADS-B receivers.