Runway Gen-4.5 is a flagship generative video model released in December 2025. Positioned as a major advancement over the Gen-4 family, it was internally developed under the codenames "Whisper Thunder" and "David." The model is designed for high-fidelity text-to-video and image-to-video generation, prioritizing cinematic motion quality, physical accuracy, and strict prompt adherence.
At its release, Gen-4.5 achieved top rankings on independent benchmarks, including the Artificial Analysis text-to-video leaderboard and Video Arena, with an Elo score of 1,247. The model features significant improvements in temporal consistency, allowing for stable character details, fabric movements, and realistic fluid dynamics across frames. It supports advanced camera choreography and multi-element scene compositions, making it suitable for professional production and rapid prototyping.
Technically, the model is optimized for high-performance inference on NVIDIA Hopper and Blackwell architectures. It is capable of generating HD videos up to 15 seconds in length with broadcast-quality resolution, providing creators with granular control over lighting, atmospheric effects, and character emotions without requiring complex prompting.