How fast can the fastest jet fly?

The fastest jet ever recorded is the North American X-15, which reached a speed of 4,520 miles per hour (7,274 kilometers per hour) during a flight in 1967. This experimental rocket-powered aircraft achieved speeds that far exceed those of conventional jets. In comparison, modern military jets, like the Lockheed Martin SR-71 Blackbird, can fly at speeds around 2,193 miles per hour (3,529 kilometers per hour). However, these speeds are significantly slower than the X-15's record.