Kuaishou's Kling 4.0 Doubles Native Video Length to 30 Seconds as the China AI Video Race Escalates

Kuaishou's AI video unit Kling has announced Kling 4.0, its next-generation video generation model, with a full launch scheduled for October and the lighter Kling 4.0 Flash already in limited early access since September 28 for premium subscribers. The upgrade is framed as a direct answer to ByteDance's Seedance 2.5, which has become many creators' default tool since its July debut, with Alibaba and MiniMax competing on price below both.

The headline spec is duration: single-generation clips now run up to 30 seconds natively, double the previous 15-second ceiling, with long takes and continuous narrative supported. Creators can pin up to 10 keyframes to choreograph scenes — fixing a character's opening position, mid-action and ending before the model fills in transitions — and combine up to 15 multimodal references per task: as many as 10 images, 5 video clips and 7 subjects in a single generation.

On the professional side, Kling 4.0 adds 4K and 1080p 10-bit HDR output (coming soon) with 21:9 widescreen support, which Kuaishou says keeps highlights from blowing out in high-contrast scenes and gives colorists more latitude. The model handles large camera moves — high-speed motion, tracking, orbiting shots — with improved stability, and lip-sync accuracy has been tuned for natural dialogue. Prompt input capacity rises to 8,000 tokens, and a continuation feature can extend clips to two minutes through multiple re-generations when it ships. Multilingual support spans nine languages plus regional Chinese and English accents, and the model can render text, emoji and logos.

The commercial backdrop matters as much as the specs. Kling completed an independent financing round in July of roughly $3 billion at an approximately $18 billion post-money valuation — the largest single round in the global AI video sector this year — with Kuaishou retaining majority control, and the unit has been positioned for a potential future listing. Annualized revenue had passed $500 million by March, per company disclosures, making Kling one of the few Chinese video models with a demonstrated subscription-plus-API business. (Capability claims in this report are from Kuaishou's announcement and have not been independently benchmarked.)

Early user reaction, at least in the comments under Kuaishou's official announcement, has been measured — with pricing and real-world capability the questions creators keep asking. That's the pressure point Jefferies analysts flag: against ByteDance's ecosystem and Alibaba's cheap alternatives, Kling's edge depends on whether quality gains justify its price. Morgan Stanley, by contrast, sees the rendering improvements as a positive catalyst.

The strategic logic is clear enough: in AI video, native length, controllability and pro-grade output are the axes on which enterprise and creator budgets get decided, and 15-to-30-second generation is the difference between a demo toy and a production tool for advertising. Kling 4.0 is Kuaishou's bid to keep its lead in the world's most competitive video model market — and its biggest monetization test yet.