GR00T N1.5

Isaac GR00T N1.5 is the first update to NVIDIA's open, fully customizable foundation model for humanoid reasoning and skills, announced at COMPUTEX on May 19, 2025. The base GR00T N1 model has roughly 2 billion parameters and uses a dual-system architecture inspired by fast and slow thinking: a vision-language-action backbone (System 2) paired with a flow-matching diffusion transformer (System 1) that produces continuous motor actions. N1.5 improved on the base release alongside the GR00T-Dreams blueprint for generating synthetic motion data to close the robotics data gap.

The model weights are distributed under the NVIDIA Open Model License Agreement, which permits commercial use with attribution, and the surrounding code is Apache 2.0. Weights, training data, and benchmark tasks were released on Hugging Face and GitHub. Humanoid and robotics developers including Agility Robotics, Boston Dynamics, Fourier, NEURA Robotics, and XPENG Robotics adopted the Isaac platform technologies announced alongside it.