The Nintendo Switch successor, Switch 2, has been in development since the year 2019, according to President Shuntaro Furukawa.
Furukawa recently confirmed (via Genki_JPN) that Nintendo began development of the Switch 2 as an official internal project around the year 2019. Though, he pointed out that the company is constantly conducting R&D for new hardware, including basic technical research. Recently, official court papers from the lawsuit between Nintendo and accessories manufacturer Genki had also mentioned that formal hardware development beginning around 2019.

Furthermore, in an issue of the Ask the Developer feature on the official Nintendo website, Tetsuya Sasaki, a member of the Technology Development Division, had stated that the company knew it would continue to develop new gaming consoles after the launch of the original Switch, so it needed to get ahead of itself and start sowing the seeds of ideas for what it could do with the next console.
Sasaki mentioned that hardware development takes time, and if Nintendo hadn’t started early, the software development environment (SDK) that’s needed afterwards wouldn’t have been ready in time. According to him, the company started by actively gathering information each day on different kinds of technologies and the results they could achieve. In that sense, he said that development of the Nintendo Switch 2 began even before 2019.
A recent leak of Nintendo Switch 2 hardware allowed YouTuber Geekerwanhe to conduct a benchmark of its CPU and GPU, revealing major upgrades over the original Switch, with a chip that is more advanced and larger in scale than initially expected. The custom SoC, codenamed T239, is 207mm² in size, nearly double the Tegra X1 (118mm²) used in the original Switch. It’s even larger than chips like the RTX 3050 Ti (mobile), Apple’s M2, AMD’s Ryzen 7840H, and Qualcomm’s X Elite. The die is labeled with a 2021 tape-out date, around two years after the console’s development began.