Seedance 2.1 AI

https://seedance21ai.org/Seedance 2.1 is an upgraded end-to-end AI video generation model developed by ByteDance. It achieves comprehensive improvements in image quality, dynamic stability, narrative performance and audio-video coordination compared with previous versions, serving as an all-round video creation tool for individual and commercial scenarios. Adopting a dual-branch diffusion Transformer architecture, it overcomes the technical shortcomings of traditional AI video tools and solves common industry problems such as image distortion, character distortion, shot fragmentation and audio-video desynchronization. Its core functions cover text-to-video, image-to-video, video extension and motion replication, fully meeting diverse creation needs for short videos, e-commerce promotion, film storyboards and brand advertisements. Equipped with powerful detailed understanding and instruction adaptation capabilities, the model accurately analyzes refined commands about scene atmosphere, character movements, camera motions and light and shadow tones. It automatically realizes professional camera movements and diverse shot types to create videos with smooth rhythms. With upgraded multi-shot narrative technology, it maintains consistent character images, costumes and scene styles across shot switches, avoiding incoherent frames. Its biggest technical highlight is native audio-video synchronous generation. It produces matched background music, environmental sound effects and human voices without post-synthesis, supporting multi-language phoneme-level lip synchronization that conforms to real physical rules and greatly reduces post-editing costs. Supporting commercial-grade output, it generates HD videos from 1080P to 2K with a maximum duration of 60 seconds and multiple aspect ratios including 21:9 cinematic widescreen. It optimizes character dynamics, material textures and light and shadow details for more realistic textures and natural motions. It supports lightweight web-based creation for individual users and enterprise API access that can be seamlessly integrated into editing and e-commerce operation workflows to realize batch video production, greatly lowering the technical threshold and time cost of professional video production.