Kling 4.0 Doubles AI Video Length to 30 Seconds. Here's What You Can Use Now and What Arrives in October.

English-language coverage of Kling 4.0 summarizes it as longer clips and "more than a dozen references". Kling's own announcement, published in Chinese, is more specific about the limits and much clearer about which features are live and which are still promises. That distinction matters if you're deciding whether to change video tools this month.

What's available now, and what isn't

The specs, as Kling states them

• Length: up to 30 seconds in one generation, double the previous maximum per Bloomberg, with long takes and continuous narrative.
• References: up to 15 multimodal references per job, combining at most 10 images, 5 videos, and 7 subjects.
• Keyframes: up to 10 per video to pin down how specific moments look.
• Prompts: up to 8,000 tokens, with the model expanding and polishing shorter prompts.
• Format: 21:9 ultra-wide, plus stereo audio and improved lip sync.
• Editing: add, change, or remove subjects and backgrounds in an existing video, and change style, weather, color, material, or camera angle.
• Languages: Chinese, English, Japanese, Korean, Spanish, Portuguese, German, French, and Hindi, with several regional accents and dialects.

Why now

Kling now operates from its own offices, independently of Kuaishou, which still holds a majority stake. It raised $2.8 billion in July from investors including Alibaba, Tencent, and Baidu at a valuation of about $18 billion, Bloomberg reports, and a Hong Kong listing is being considered. Bloomberg describes ByteDance's Seedance 2.5, launched in July, as the go-to choice for many creators, with Alibaba and MiniMax gaining ground on price-to-performance. Kling got a lift when OpenAI shut down Sora, and has been among the fastest to earn money from video through subscriptions and developer access.

What this means if you make AI video

The 30-second limit and 10 keyframes are the practical upgrades: fewer clips to stitch, and more control over how a scene develops. But unless you're on Kling's top annual plan, you can't try any of it yet, and the two features that matter most for professional work, HDR output and two-minute extensions, have no date. Test Flash if you have access, and wait for the October release before committing a production pipeline.