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 gathering by volunteers with ADS-B receivers and from satellite-based ADS-B receivers. The service is available via a web page or mobile device apps. The Guardian considers the site to be "authoritative". History The service was founded by two Swedish aviation enthusiasts in 2006 as Flygbilligt.com and later Flygradar.nu for Northern and Central Europe. The service was opened in 2009, allowing anyone with a suitable ADS-B receiver to contribute data. The service received extensive exposure in 2010, when international media relied on it to describe the flight disruption over the North Atlantic and Europe caused by the Eyjafjallajökull volcano eruptions. Flightradar24 came at the turn of the month July-August 2010 as an iOS application. In 2014, it was used by multiple major news outlets following several high-profile crashes: in March after the disappearance of Malaysia Airlines Flight 370, in July after Malaysia Airlines Flight 17 was shot down over Ukraine, and in December when Indonesia AirAsia Flight 8501 went missing. Flightradar24 reported that its web traffic increased to around 50 times normal, which caused some access congestion to users. In November 2015, The Guardian newspaper reported that Metrojet Flight 9268 en route to Saint Petersburg from Sharm el-Sheikh International Airport had broken up in the air based on information available from Flightradar24. From 3 March 2020, ADS-B data collected by satellite was made available to all users. Aircraft located using satellite data are coloured blue on the map, and yellow if located by terrestrial receivers. In February 2022, during the Russian invasion of Ukraine, the website crashed due to an influx of visitors tracking flights in and around Ukraine. In March 2022, the site was used to see the playback of the crash of China Eastern Airlines Flight 5735. In August 2022, the plane carrying Nancy Pelosi to Taiwan, SPAR19, became the most tracked flight to date, tracked by over 708,000 people as it landed in Taipei, with over 2,900,000 following at least a portion of the flight. In September 2022,