--- id: "2026-07-31-seedance-2-5" url: "https://postcutoff.com/e/2026-07-31-seedance-2-5/" as_of: "2026-10-25T23:49:00+01:00" date: "2026-07-31" date_precision: day category: media-generation importance: 3 confidence: high status: [Confirmed] sources: 3 editor: human editor human_review: null version: "2026-10-25" --- As of: 2026-10-25 23:49 CET. Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/ Canonical page: https://postcutoff.com/e/2026-07-31-seedance-2-5/ # ByteDance Seedance 2.5 video model Full title: ByteDance releases Seedance 2.5: 30-second one-take audio-video clips with up to 50 references; a 4K film-production version follows on Oct 23 On July 31, 2026 ByteDance Seed released Seedance 2.5, a joint audio-video generation model that makes a 30-second clip with synced sound in one pass (up from 15 s) and takes up to 30 images, 10 video clips and 10 audio clips as references. It became one of the most used video models in AI-made media; on Oct 23 Volcano Engine opened a 4K, 10-bit 'Seedance 2.5 4K' version to selected film and TV customers. ## Key facts - Announced July 31, 2026 by ByteDance Seed; rolled out in Jimeng AI and Doubao Pro, with API access via BytePlus ModelArk 'coming soon' at launch (ModelArk id dreamina-seedance-2-5-260628, see the model file) - Up to 30 s per generation in one take (previously 15 s), extendable over several rounds while keeping characters, setting and narrative consistent - Unified audio-video joint generation: sound and picture made together and kept in sync - References in a single pass: up to 30 images, 10 video clips and 10 audio clips; also clay-render, motion and creative references - Editing: timestamp-level targeted audio/video edits, green screen, camera-perspective and reference-based editing - Seedance 2.5 4K (Oct 23, 2026, Volcano Engine): 4K output with 10-bit colour, further training for facial expressions and fine motion, a 480p draft mode for cheap storyboard previews; trials for selected enterprise customers only, some Chinese and overseas film and post-production firms testing (TechNode citing IT Home); no price given - Artificial Analysis text-to-video leaderboard (read 2026-10-25): #5, Elo 1158 - Widely used in the AI-made videos in this dataset (e.g. the Claude Pop genre) ## What happened ByteDance's Seed team released Seedance 2.5 on July 31, 2026. It doubles the single-pass length to 30 seconds and generates sound and picture together, so dialogue and effects stay in sync. A single prompt can carry up to 50 reference files (images, clips and audio), and edits can target a time range in the clip. It launched in ByteDance's consumer apps (Jimeng, Doubao) with the API following on BytePlus ModelArk. On Oct 23, 2026 ByteDance's cloud arm Volcano Engine opened a 4K version for film and television work, with 10-bit colour and a low-cost 480p draft mode for testing shots. Only selected enterprise customers can try it so far. ## Why it matters Seedance 2.5 is one of the two or three video models most creators used in the second half of 2026, and the 4K version marks a push from social clips toward professional production. Third-party pages had claimed native 4K for the July model, but BytePlus pricing listed 4K as unsupported; the October version is the first official 4K release. ## Your AI and this story - GPT-6 Astra (training cutoff April 2026): 92 days after its cutoff - Claude Opus 5.5 (training cutoff June 2026): 31 days after its cutoff - Gemini 4 Argon (training cutoff March 2026): 122 days after its cutoff - Grok 4.7 (training cutoff May 2026): 61 days after its cutoff ## Sources 1. [ByteDance Seed: Introducing Seedance 2.5 (July 31)](https://seed.bytedance.com/en/blog/one-take-creation-flexible-referencing-introducing-seedance-2-5) (seed.bytedance.com, official) 2. [TechNode: ByteDance launches Seedance 2.5 video generation model (July 31)](https://technode.com/2026/07/31/bytedance-launches-seedance-2-5-video-generation-model/) (technode.com, press) 3. [TechNode: ByteDance launches Seedance 2.5 4K video model for film production (Oct 23)](https://technode.com/2026/10/23/bytedance-launches-seedance-2-5-4k-video-model-for-film-production/) (technode.com, press) ## Changes - 2026-10-25 (filed): Created with the Oct 23 4K version ## Related - 2026-09-28: [Kuaishou's Kling unveils Kling 4.0](https://postcutoff.com/e/2026-09-28-kling-4-0/index.md) - 2026-09-22: ["Claude Pop": music videos made by Claude Opus 5.5 for the AI-doom song "I'm Upping My P(doom)" become a genre](https://postcutoff.com/e/2026-09-22-claude-pop-genre/index.md) - 2026-08-24: [Alibaba Wan 3.0 video model](https://postcutoff.com/e/2026-08-24-wan-3-0/index.md) - Models: [Dreamina Seedance 2.5](https://postcutoff.com/m/seedance-2-5/) (`seedance-2-5`)