Runway Unveils Gen-4.5 Video Model, Bringing Advanced Physics to All Paid Users

Details

• Runway has launched Gen-4.5, an incremental update to its leading text-to-video generator, initially introduced as Gen-4 in mid-2025.
• The primary enhancement is the inclusion of a physics engine that simulates vehicles, objects, and character movement with authentic weight, momentum, and force.
• This upgrade targets industries such as film pre-visualization, advertising storyboarding, and social video, where lifelike physical motion is essential.
• Gen-4.5 is available now to all paid tier subscribers—Standard, Pro, and Unlimited—without extra charges or token increases.
• Users can now access a “Physical Accuracy” slider in both web and desktop apps; higher settings make motions smoother, though they add about 15 percent to processing times.
• API integrations remain fully compatible, allowing seamless upgrades in existing automation with just a parameter change.

Impact

This release intensifies competition in AI video generation, challenging rivals such as Pika, Luma Dream Machine, and Stability to close the realism gap. By bundling the upgrade into current subscription plans, Runway could trigger price cuts across the sector and entice creatives to shift more workflow to generative tools. The model's improved accuracy may also align with industry calls for digital safety, offering further legitimacy as regulatory scrutiny of synthetic media grows.