Flight testing On 10 December 2010, the first J-20 prototype was observed undertaking high-speed taxiing tests around the Chengdu Aircraft Design Institute (CADI) facilities before the maiden flight. After the successful flight, a ceremony was held, attended by the pilot, Li Gang, Chief Designer
Yang Wei and General Li Andong, Deputy-Director of General Armaments. On 17 April 2011, a second test flight of an hour and 20 minutes took place. On 5 May 2011, a 55-minute test flight was held that included retraction of the landing gear. On 26 February 2012, the first prototype J-20 performed various low-altitude maneuvers. On 10 May 2012, the second prototype (numbered "2002") underwent high-speed taxiing tests, and flight testing that began later that month. On 16 January 2014, the third J-20 prototype was revealed, showing new intakes, embedded engine nozzles, and stealth coating, as well as redesigned vertical stabilizers, and an
Electro-Optical Targeting System. This particular aircraft, numbered "2011", performed its maiden flight on 1 March 2014 and is said to represent the initial pre-serial standard. The fifth prototype, numbered "2013", took off on 29 November 2014. On 13 September 2015, a new prototype, marked "2016", began testing. It had noticeable improvements, such as apparently modified DSI bumps on the intakes. The DSI changes suggested the possibility of more powerful engines being used than its predecessors, likely to be an advanced 14-ton thrust derivative of the Russian
AL-31 or Chinese Shenyang WS-10 turbofan engines. By 2020, the J-20 is scheduled to use the 18–19 ton
WS-15 engine. The trapezoidal flight booms around the engines were further enlarged, possibly to accommodate rearwards-facing radars, electronic countermeasures, and jamming equipment. The fuselage was extended to the engine's exhaust nozzles. Compared to its "2014" and "2015" predecessors, the engine's surface area is further embedded inside the stealthy coating, providing greater rear-facing stealth against enemy detection. On 24 November 2015, a new J-20 prototype, numbered "2017", took to the sky. The most significant change in the new prototype was the reshaped cockpit canopy, which provides the pilot with greater visibility. The lack of other design changes suggested that "2017" is very close to the final J-20 production configuration. Since '2017' was likely the last J-20 prototype, the low rate initial production (LRIP) of the J-20 is likely to begin in 2016. Chinese media reported that the design of the J-20 was
frozen and finalized, as formal ceremonies were held for the prototype "2017" after completing the flight testing. The LRIP version later appeared in December 2015. In March 2017, Chinese media reported that the fighter entered service. But it still faced a series of technical challenges that needed to be tackled, including the reliability of its WS-15 engines, the aircraft's flight control system, stealth coatings, hull materials, and infrared sensor. In September 2017, a newly built J-20 prototype (numbered "2021") was flight testing with Chinese-made WS-10 Taihang engines, featuring sawtoothed serration edge on its afterburning nozzles. The J-20 with indigenous WS-10C engines began production in 2019. The WS-15 reportedly required further development after failing final verification testing at the end of 2019. In October 2021, a twin-seat J-20 prototype, dubbed J-20S by analysts, was spotted taxiing inside Chengdu Aircraft Corporation facilities. In the same month, new J-20 two-seater variant began flight testing. In December 2022, the prototype "2051" in yellow premier coat took flight. The new prototype had a redesigned canopy section and was speculated for engine and thrust-vectoring testing Despite the lack of clear pictures, circumstantial evidence such as a photo of the engine installation ceremony, lack of censorship by the authorities, and modified airframe suggested the WS-15 was evidently mounted, though
Janes Information Services noted the engines on trial apparently lacks the
thrust vectoring control (TVC) paddles, which could be added later. According to editor of Beijing-based
Aerospace Knowledge magazine, vector thrust control and
variable cycle engines were "likely under development". In 2024, clear photo evidence confirmed that J-20 prototypes took flight with the WS-15, and the engine approached the final stage of testing before serial production. Between November 2021 and March 2025, five separate J-20S prototypes were built for flight testing. In July 2016, pre-production models with dark-grey paint and low visibility insignias were spotted inside a
Chengdu Aircraft Corporation (CAC) facility. The production rate indicated an intended
initial operational capability (IOC) date of around 2017–2018. In October 2017, Chinese media reported that CAC initiated the serial production for the J-20 and is on a path towards achieving
full operational capability with the People's Liberation Army Air Force (PLAAF). State media described the CAC's production rate as "stable", meaning achieving a regular production rate for minimal economies of scale. The production rate was expected to be three aircraft per month. In 2019, CAC began manufacturing J-20 fitted with Chinese-made WS-10 Taihang engines. In January 2022,
United States Air Force (USAF) analyst Derek Solen estimated 50 to 74 fighters were in service based on open-source intelligence. In August 2022, USAF analyst Li Xiaobing reported that over 150 had been delivered; claims of 150 being in service had been made in 2021. In late 2022, Andreas Rupprecht estimated total production at 208 aircraft - including pre-production aircraft - based on interpreting serial numbers. The
International Institute for Strategic Studies (IISS) reported more than 140 aircraft in service in 2022. According to Bronk, the aircraft at the 2022
China International Aviation & Aerospace Exhibition had visible improvements to
manufacturing tolerance and quality control. In 2023, the reported number of J-20s exceeded the 187 F-22 airframes. IISS reported that more than 200 aircraft were produced by the end of 2023. In mid-2024,
Janes Information Services estimated that approximately 195 aircraft were in PLAAF service, with more than 70 aircraft inducted between July 2023 and June 2024.
The Diplomat reported up to 250 aircraft were produced by June 2024, with an annual production rate of 100 aircraft per year. A conservative estimate suggested the number of aircraft could reach 800 by 2030. In September 2025, images showed that the J-20 fleet exceeded 300 aircraft.
Training Pilot training for the J-20 started as early as March 2017, after the fighter entered limited service in the initial operational capability (IOC) phase. During the IOC phase, the fighters are equipped with radar reflectors, also known as the
Luneburg lens, to enlarge and conceal the actual radar cross-section. The J-20 participated in its first combat exercise in January 2018, practicing beyond-visual-range maneuvers against China's
fourth-generation fighters such as
J-16 and J-10C. The exercise was reported to be realistic. Training with mixed generations allows pilots to become familiar with fifth-generation aircraft, and to develop tactics both for and against them. Chinese Ministry of National Defense also revealed that J-20 has conducted night confrontation missions during several coordinated tactical training exercises. The J-20 participated in its first over-ocean combat exercise in May 2018. In April 2022, the J-20 is confirmed to be engaged in regular maritime patrols in the
East China Sea and the
South China Sea for routine training missions, in a statement released by CAC. In March 2023, Chinese state media reported that the PLAAF uses J-20 fighters to simulate the F-35 in surface strike missions during
opposing force training. The exercise tested the command chain and kill chain integration between the
PLA Ground Force and Air Force, with two branches sharing real-time data for combined air defense missions and training tactics against stealth fighters.
Deployment On 12 December 2016, at least six J-20s were observed in PLAAF air bases, with tail numbers 78271-78276 identified. Another six were believed to be ready for delivery by the end of December 2016. On 9 March 2017, Chinese media revealed that the J-20 had entered service in the Chinese Air Force, The PLAAF began inducting J-20s into combat units in February 2018, On 27 August 2019, the Central Military Commission of the People's Liberation Army approved the J-20 as the PLAN's future primary fighter, beating out the
Shenyang FC-31. Arguments for the J-20 state that the plane is far more advanced, longer-ranged, and carries a heavier payload than the FC-31, while those supporting the FC-31 argued that it is cheaper, lighter, and far more maneuverable than the J-20. The J-20 would likely be commissioned upon the
Type 003 aircraft carrier under construction, however, the length of the J-20 means that it has to be shortened to be considered operable on an aircraft carrier. On 26 June 2021, Chinese state media reported that J-20 fighters were deployed to PLAAF units monitoring the East China Sea and
Taiwan Strait. Analysts suggested that the PLAAF aimed to equip at least one to two
brigades in each of the five
theater commands before 2026. By 2022, J-20s were deployed in combat units in all five theater commands; this was officially confirmed in September 2022. In March 2022, USAF general
Kenneth Wilsbach confirmed that USAF F-35s have encountered J-20s deployed over the East China Sea. In April 2022, Chinese state media reported J-20 started regular patrol in the South China Sea. According to the
China Aerospace Studies Institute (CASI), three combat brigades received the J-20 by 2021, another three by 2022, and another two by 2024. In July 2025, the twin-seat J-20S variant was observed painted in PLAAF camouflage and serial numbers associated with the PLAAF 172nd Air Brigade, indicating the variant has either entered or is close to entering service.
Summary of program milestones The following is a table of significant milestones in the J-20 program history as gleaned from public sources and cited previously in the present article: ==Variants==