How China's J-20 fighter jets compare to US F-35s (2024)

China's Chengdu J-20 fighter jet, despite its advanced capabilities, falls short in comparison to the U.S.-made F-35 jet, an expert has argued.

"The J-20 has a larger internal fuel payload than the F-35, but it is also larger. The J-20's range will be similar to or shorter than the F-35's. Also, unlike the F-35, the J-20 cannot carry air-to-ground bombs internally, which is a fundamental limitation of the J-20," Kim Minseok, a research fellow at the Korea Defense and Security Forum, told Newsweek in an interview.

Introduced in 2017, the J-20 made China the third country after the U.S. and Russia to field operational fifth-generation stealth fighters designed to evade radar detection. Estimates suggest China's military may have as many as 250 jets in service.

Equipped with an array of sensors and capable of carrying China's longest-range PL-15 air-to-air missiles, the J-20 is being continually upgraded. Its primary role is air superiority, giving China an edge over India's aging fighter fleet along their tense Himalayan frontier. The J-20 jets were recently seen at the Shigatse Air Base in Tibet, near the border with India, Newsweek reported recently.

The WS-10 engine was designed as the original engine for the J-20's initial prototypes, while there was a suggestion that a more powerful engine may be developed for the jet.

"It has been pointed out that China's WS-10 engine is similar to the US F101 engine, but it is clear that Chinese jet engines have developed without direct U.S. support. The J-20's WS-15 engine, while powerful, is still expected to be inferior in performance to its American counterpart," Kim told Newsweek.

Since its introduction, the J-20 has undergone a series of upgrades, including a new and powerful WS-15 engine seen during a 2023 test in Chengdu.

Last year, four days after the Paris Air Show ended, a video surfaced of China's J-20 stealth fighter making its first public flight equipped with a pair of domestically built WS-15 engines. The Aviation Industry Corporation of China hasn't commented on the video, but its persistence online suggests the state-owned aerospace manufacturer, and by extension, Beijing, wants it seen publicly.

While not the first time the WS-15 has powered the J-20, footage shows the fighter flying with one WS-15 and an older engine model in 2022 during testing. After years of delays in China's efforts to develop an advanced fighter jet engine domestically, having two installed marks a sign of maturity for the cutting-edge turbofan.

"The WS-15 provides higher thrust than the interim engines, and among other features will enable the J-20 to achieve even more impressive kinematic performance than it presently has. It will also enable consistent and true supercruise (supersonic speed without afterburners), further augmenting the aircraft's capability in its general air superiority role," aviation affairs expert Rick Joe wrote for Asian security affairs magazine, The Diplomat, on August 1, 2023.

The F-35 jet is powered by Pratt & Whitney's F135 engine, which was developed for all the three versions of the jet, including the F-35A with Conventional Take-Off and Landing (CTOL), F-35B – Short Take-Off, Vertical Landing (STOVL) and F-35C – Carrier Variant.

Pratt & Whitney's F135 engine, producing over 40,000 pounds of thrust, is the powerplant for the F-35 fighter jet. It boasts an unmatched low-observable signature, world-class thermal management, and the most advanced integrated engine control system ever created.

Newsweek contacted China's Ministry of Defense and the U.S. Department of Defense for comment.

According to Pratt & Whitney, the F135 is the most powerful and advanced fighter engine ever produced and the most dependable. It demonstrates a significant improvement in readiness and reliability over fourth-generation fighter engines.

The engine delivers unrivaled performance, enabling operations in the most advanced threat environments. It redefines what's possible for customers and their missions, according to Pratt & Whitney.

"The J-20 is faster than the F-35 but the Lightning II has lower radar cross-section. The J-20 does not have a cannon which could mean that designers were not envisioning it as a dogfighting machine. The F-35 is lighter, which may give it an edge in aerial combat," wrote Brent Eastwood, a fellow at the Washington think tank R Street Institute and a former infantry officer, for international affairs magazine National Interest.