Kuaishou announced Kling 4.0 on 28 September 2026 and opened a faster Flash version to its top-tier annual subscribers the same day. The headline is length: up to 30 seconds in one generation, double Kling 3.0. The full model is due in October. Here is what is confirmed, what is still marked coming soon, and what it changes for a short-form calendar.
Kling 4.0 is Kuaishou's next-generation video model, announced on 28 September 2026: the full model generates 3 to 30 second clips with two-channel stereo audio and multilingual lip-sync, accepts up to 10 keyframes and up to 15 references in one prompt, and targets 720p, 1080p and 4K output with 10-bit HDR, with 4K and HDR marked as coming soon. Kling 4.0 Flash, a faster version limited to 720p and 3 to 20 second clips, opened as a closed beta for top-tier annual subscribers the same day; the full release is due in October 2026 and API pricing has not been published.
For marketers the change is length plus control: a 30-second ad with a planned shot list can come out of one generation instead of a stitched sequence of 10 or 15 second clips.
| Maker | Kuaishou Technology |
|---|---|
| Announced | 28 September 2026 (some outlets date it 27 September, a time zone difference). Full release due in October 2026, exact date not verified |
| Versions | Kling 4.0 (full) and Kling 4.0 Flash (faster, closed beta for top-tier annual subscribers from 28 September 2026) |
| Max clip length | 3 to 30 seconds on the full model; 3 to 20 seconds on Flash |
| Resolution | Full model: 720p, 1080p and 4K, plus 10-bit HDR at 1080p and 4K, with 4K and HDR marked coming soon. Flash: 720p only |
| Native audio | Yes: two-channel stereo with lip-sync in multiple languages |
| Control | Up to 10 keyframes, up to 15 reference inputs and prompts of up to 8,000 tokens |
| Aspect ratios | Adds a 21:9 cinematic ratio alongside the usual 16:9, 1:1 and 9:16; the complete list is not verified |
| Frame rate | Not verified |
| Pricing | Not published at announcement. Flash is included for top-tier annual Kling subscribers during the beta; API pricing and timing not verified |
Versus Kling 3.0 (5 February 2026): maximum clip length doubles from 15 to 30 seconds, audio moves to two-channel stereo, control grows to 10 keyframes and 15 references with long prompts, a 21:9 ratio is added, and 10-bit HDR is promised at 1080p and 4K. Kling 3.0 already had native 4K; on 4.0, 4K and HDR are announced as coming soon rather than live at launch. Kling 3.0 and 3.0 Turbo remain available while 4.0 rolls out.
At announcement, only Kling 4.0 Flash is usable, as a closed beta inside the Kling AI web platform and app for top-tier annual subscribers. The full model is due on the Kling platform in October 2026; API availability and third-party reseller access are not yet confirmed.
Thirty seconds is the length that matters. Most short-form ads that convert run 15 to 30 seconds, and until now every frontier model topped out around 15, which meant stitching two or three generations and fighting continuity at every cut. A single 30-second generation with up to 10 keyframes is close to directing a full ad from a shot list: hook, problem, product, proof, call to action.
Be careful with the launch-week claims. 4K and HDR are announced, not live, and the Flash beta that people can actually use is 720p and capped at 20 seconds. Plan tests around what Flash does today and treat the full-model specs as a roadmap until it ships.
The usual QA still applies: hands, on-screen text and logos need a human check, and longer clips give a model more room to drift, so review the back half of every 30-second render as closely as the hook.
Generate anywhere, publish natively to TikTok, Reels, Shorts and LinkedIn, attribute signups and sales to every post.
When you get access, generate full 30-second hero ads in Kling 4.0, then upload them into Fastlane to schedule weeks ahead and publish natively to TikTok, Instagram Reels and YouTube Shorts, with signups and sales attributed to each post so you can see whether the longer cut beats your 15-second versions.
Fastlane fills the rest of the calendar from your website URL without waiting on any one model: AI UGC videos with 1,000+ hyper-realistic characters, slideshows, hook + demo videos and memes, remixed from 25,000+ trending videos. Free plan, no credit card.
Kuaishou announced Kling 4.0 on 28 September 2026 and opened Kling 4.0 Flash as a closed beta for top-tier annual subscribers the same day. The full model is due in October 2026.
Up to 30 seconds per generation on the full model, starting from 3 seconds. Kling 4.0 Flash is capped at 20 seconds.
It is announced for 720p, 1080p and 4K with 10-bit HDR at 1080p and 4K, but 4K and HDR are marked as coming soon. The Flash beta outputs 720p only.
Kuaishou has not published Kling 4.0 pricing. Flash is available in beta to top-tier annual subscribers, and API pricing has not been announced.
Kling 4.0 doubles clip length to 30 seconds, adds stereo audio, 10 keyframes, 15 references and a 21:9 ratio. Kling 3.0 is generally available today with native 4K, 15-second clips and published API pricing.
Specs verified against the sources above on October 1, 2026. Model access and pricing change often; check the maker's page before you build on any number here.
Join 50,000+ founders and marketers publishing the same video to TikTok, Instagram, YouTube and LinkedIn. Free to start.
