Seedance 2.5, ByteDance's latest video generation model, is now available on Runway. The headline feature is straightforward: you can generate a single, coherent video clip up to 30 seconds long from a text prompt and up to 50 reference inputs spanning images, video, and audio. That's a meaningful jump from where AI video generation has been sitting.

There's a small asterisk on the "1080p" framing in Runway's announcement. Seedance 2.5 on Runway outputs at 480p and 720p. For 1080p, you use Seedance 2.0. The two models coexist on the platform and are optimized for different jobs , more on that below.

What actually changed from 2.0

Since Seedance 2.0, ByteDance noticed a shift in what users expect from video models: from generating a clip to completing a creative work. Seedance 2.5 builds on the unified multimodal audio-video architecture of 2.0, delivering major breakthroughs in long-form storytelling, multimodal reference, and editing. The three upgrades that matter most in practice:

• Longer clips: Up to 30 seconds per generation in a single pass, with support for multiple rounds of extension. Seedance 2.0 caps at 15 seconds.
• More references: Up to 50 multimodal reference inputs per generation , 30 images, 10 video clips, and 10 audio clips , far above Seedance 2.0's 9 images and 3 clips.