Kling 4.0 went on sale on 15 October with 30-second clips, twice the 15 seconds of 3.0, and keyframes. Kling already offered 4K in April, so 4.0 sells longer clips and more control. The discount is a bid for usage.
Kling's newest video model is on sale, but two features in its marketing are not ready. On 15 October the company's release history logged a "Major" entry titled "Meet All-New Kling 4.0!". Its blog pages now carry a banner reading "Kling 4.0 Available Now" with 10% off for a limited time. The developer model page still says the model "will officially launch in October".
The launch is staged and discounted. What has shipped is native 30-second clips, up to 10 keyframes, and up to 15 reference items. None of that raises resolution. Kling is cutting prices to build usage on the model it wants customers to use, which now makes clips twice as long.
The calendar shows the staging. Kling 4.0 Flash, the cheaper variant, reached a limited group of users on 28 September. The company's blog post says Ultra Yearly subscribers could use it from that date. The flagship followed on 30 September as early access, "with a wider rollout coming in October". The release note is dated 15 October, and the banner was live on 16 October.
Kling's own precedent makes the point. It logged Kling 3.0 on 31 January as "Fully Rolled Out". No Kling page uses that phrase for 4.0. Paying users can buy the model today, but the developer page and blog still point to a wider October rollout. It is not yet generally available.
4.0 is not a resolution upgrade. Kling's release history shows "native 4K output" on 23 April in the 3.0 family. The 4.0 spec table lists the same range of 720p, 1080p, and 4K.
The changes are length and control. Kling's comparison with 3.0 shows clip length rising from 3 to 15 seconds to 3 to 30 seconds. References rise from 7 to 15 assets. Single-channel audio becomes two-channel stereo.
The two headline additions are still waiting. The blog says 10-bit HDR output at 4K and 1080p "is coming soon". HDR means a wider range of brightness and colour. Video extension of up to 2 minutes carries the same "(coming soon)" tag. The comparison page and spec table both present HDR as a 4.0 trait, so a buyer who skips the fine print could think it is live. It is the only picture-quality change in this release, and it is unavailable. A user who extends a clip today still works within the 30-second ceiling per generation.
Flash is a different product. Per Kling's developer page, it is capped at 20 seconds and 720p, and is listed as 8-bit standard dynamic range. Its user guide says it does not currently support start and last frames or multiple keyframes. It is a draft tier with shorter clips, lower resolution, and fewer controls than the flagship. Kling positions it for frequent creation, so Flash carries the volume while the flagship does finished work.
The money explains the promotion. Kuaishou, Kling's parent, reported Kling revenue of over RMB650 million in its first quarter results. That was up more than 300% on the year. In its second quarter release, the figure was over RMB850 million, up more than 200%. Kling revenue rose about 31% in one quarter, putting its run rate near RMB3.4 billion a year.
Kling is also taking a larger share of the group's other services line. That line rose 18.5% to RMB6.2 billion in the second quarter, and the release attributes the rise mainly to Kling. On the same round numbers, Kling was about 13.7% of that line, against about 11.6% in the first quarter. The second quarter release refers to Kling 3.0 and 3.0 Turbo. Every yuan so far came from the previous generation. The 4.0 launch falls almost entirely in the third and fourth quarters.
The discount is a statement about demand. The 10% launch cut and new subscription tiers of up to 40% off move subscribers onto the new model. The open question is whether paying users settle on Flash for volume and keep 4.0 for finished work, or whether the flagship becomes the default.
Buyers have two choices. They can lock in a subscription tier during the discount window, or stay on pay as you go and use 3.0 or Turbo until HDR and extension ship. The promotion is time limited, and it applies to a model whose HDR is unavailable. The discount buys 30-second clips and keyframes today; the HDR picture comes later. Flash at 20 seconds and 720p is the cheaper drafting option.
The later steps will probably follow the 3.0 pattern. That family added native 4K on 23 April and Turbo on 17 June. Each arrived as a feature layered onto one model family, so HDR and extension should come as further release notes. The gap between 3.0's 4K and Turbo was about eight weeks. Applied to the 30 September early access, that points to late November or December for HDR.
Kuaishou's fourth quarter results will be the first to contain a full quarter of 4.0. Kling revenue went from over RMB650 million to over RMB850 million between the first and second quarters of 2026. If growth slows to 25% a quarter from the RMB850 million base, the fourth quarter would be about RMB1.3 billion. A number below that would say the 30-second model brought discounts but not new demand.