Kling 4.0: Specs, 30-Second Limit and Kling 3.0 Compared

Kling 4.0 is the newest video model from Kuaishou's Kling AI. Kling says it became available to everyone on October 15, 2026. Kling lists up to 30 seconds per generation, and the model takes up to 10 keyframes and up to 15 reference assets. This page collects what Kling, Kuaishou, API providers and the press have published about it, puts its specifications next to Kling 3.0, and explains what you can do with it on Effect Video, where one clip currently runs up to 15 seconds. Every source was checked on October 22, 2026.

What Kling 4.0 is

Kling's own user guide, dated October 14, 2026, describes the model in one sentence.

The guide lists text-to-video, image-to-video, first and last frames, multiple keyframes and Omni Reference as the model's capabilities. In Kling's creation workspace they sit behind two entry points. Omni Reference accepts images, videos and voice profiles, and it is the default. Keyframes accepts images only and pins visuals to chosen moments on the timeline. Kling says the two cannot be combined in one generation task.

The guide's overview names the aims as steadier complex motion, more consistent results across many references and more controllable storytelling. Kuaishou's press release, dated October 16, 2026, says the upgrades center on three priorities, realism, control and professional quality.

What is new in Kling 4.0

Length comes first. By Kling's specification, Kling 4.0 can run 30 seconds as one continuous take, from a minimum of 3 seconds, in one-second steps. Kling describes the goal as long takes and continuous storytelling. The Keyframes entry accepts up to 10 images placed along the timeline, and the guide describes first frames, last frames, first-and-last-frame pairs and middle frames at any position. Prompts can reach 8,000 tokens, and Kling says the model expands a short prompt by filling in storyline, scene blocking and camera movement.

Omni Reference takes up to 15 assets per task, drawn from up to 10 images, 5 videos with 30 seconds combined, 7 elements and 3 voice profiles. Kuaishou's press release lists subject images, three-view character sheets, grid images, storyboards and wireframes as image references. Video references can steer performance, camera movement and pacing, and Kling's comparison article says a depth-map or white-model video can carry motion and spatial information. The same workflow covers editing, where up to five clips (one primary, each 3 to 30 seconds, 30 seconds in total) are changed for expressions, movement, background, camera or style while the rest of the scene stays stable. Kling calls it Creative Recreation when the pacing and shot structure of an existing video are rebuilt with new products or characters.

Audio is two-channel stereo with improved lip sync. The guide names nine languages, Chinese, English, Japanese, Korean, Spanish, Portuguese, German, French and Hindi, plus accents and dialects such as Cantonese, the Sichuan dialect and American, British and Indian English. On-screen text in those languages, emoji and logos is listed as well. Audio input accepts voice profile references only. According to the guide's FAQ, background music and sound effects are generated from the visuals.

The guide adds 21:9 to the aspect ratios (16:9, 1:1, 9:16 and Auto) and lists 720p, 1080p and 4K. The feature summary marks 10-bit HDR output and video extension, up to two minutes through repeated extension, as coming soon. The next section returns to HDR, because Kling's own pages do not describe it the same way.

Kling 4.0 release date and availability

Multiple sources agree on the main line. Kling's X account and launch video announced Kling 4.0 on September 28, 2026 as an early-access release with a wider rollout planned for October, and Kling 4.0 Flash went first to Ultra Yearly subscribers. Kling's blog post on the announcement is dated September 30. Kling's release notes and Kuaishou's press release both give October 15 as the day the full model launched, and 36Kr and Quantslant report the same date.

The sources differ on 4K and 10-bit HDR.

The launch date is settled across official and press sources. The state of 4K and 10-bit HDR is not, and Kling's own pages disagree with each other. The user guide and the release notes each call HDR output coming soon in one place and list it in their specification tables in another. The feature page marks native 4K and 1080p output as coming soon. The press release uses the present tense for HDR and the future tense for 4K, and 36Kr lists both among the launch features. This page does not promise either. Effect Video offers 720p and 1080p.

Kling 4.0 vs 3.0: what changed

Kling published its own comparison on September 30, 2026, before the full launch. The table below takes the Kling 3.0 column from that comparison, the Kling 4.0 column from the 4.0 user guide and release notes, and the aspect ratios from Kling's API documentation. It compares published specifications only. We have not run Kling 3.0 and Kling 4.0 on the same inputs, so this page makes no statement about picture quality or about which model looks better.

Kling's article points out that Kling 3.0 already supports 4K, so resolution is not the main difference. It describes the practical gains as more time, finer timeline control, richer references and more flexible editing. It also says Kling 3.0 remains useful for shorter generations, prompt-led scenes, Multi-Shot content and projects where a 15-second sequence is enough, and that Kling 4.0 fits projects that need more time, more references, more timeline control or more complex revisions.

Effect Video carries both models. The strip sets their provider, clip length, resolution and audio side by side, as offered on Effect Video.

Kling 4.0 Flash

Kling's release notes describe Kling 4.0 Flash as a model for frequent creation that combines fast generation with good value. The listed capabilities are text-to-video, image-to-video from a first frame and Omni Reference, with durations of 3 to 20 seconds, 720p output and 8-bit SDR. The guide's FAQ adds that Flash does not currently support first-and-last frames or multiple keyframes, and recommends the full model for longer videos, higher resolution and precise visual control. Atlas Cloud's write-up of the specifications repeats the 20-second, 720p and 8-bit SDR limits.

Kling opened Flash on September 28, 2026 to Ultra Yearly subscribers, and its comparison article calls the group limited. Effect Video does not offer a separate Flash option.

Kling 4.0 API access

Sources disagree most about the API, and Kling's own pages and posts disagree with each other. The table lists what each provider said when we read their pages on October 22, 2026.

Effect Video's generator uses KIE's keyframe-to-video endpoint and limits one clip to 15 seconds. KIE documents a first frame, up to eight middle keyframes and a last frame, durations of 3 to 30 seconds, 720p and 1080p, and aspect ratios of 21:9, 16:9, 9:16, 1:1 and Auto. The aspect ratio setting applies only to text-only requests, and with any frame the output follows the first frame. Kling's API pricing rules bill Kling 4.0 by total video seconds and separate requests with and without video input.

Using Kling 4.0 on Effect Video

Kling 4.0 is available in the Effect Video generator. You write a prompt and can add one photo, which becomes the first frame of the video. Clip lengths are 3, 5, 8, 10 or 15 seconds at 720p or 1080p, in 16:9, 9:16, 1:1 or 21:9. As of October 22, 2026 the longest clip is 15 seconds, half of the 30 seconds the model supports. When you add a photo, the video follows the aspect ratio of the photo, as the KIE documentation describes. The aspect setting applies to text-only prompts.

There is no sound switch for this model. Kling's guide says audio-visual synchronization is on by default, and KIE's keyframe-to-video documentation lists no audio field. Effect Video shows the total credits before you start, returns credits reserved for a generation that fails, and keeps finished videos for 7 days.

The generator does not offer clips longer than 15 seconds, reference videos, elements, voice profiles, middle and last frames, video editing and extension, 4K and HDR, or the Flash model. Kling's guide and the API providers in the table above document these features. What the generator covers is a single clip of up to 15 seconds from a prompt and one photo.

Prompt tips from Kling's guide

Kling's guide advises describing visuals directly and leaving out abstract terms. Its examples swap "premium look" for side backlighting that outlines the object's edges, a blurred background and fine matte grain on the surface. It says negative instructions can raise the chance of errors, and it names two worth writing out, no subtitles and no background music, because the model may add them by default.

For a first frame, the guide's pattern is to say that the image is the first frame and then describe what happens next. Its FAQ recommends starting with one clear sentence about the subject, scene, action and emotion, then adding only the details that change the result, such as camera work, timing and audio. Longer prompts are not always better, the guide says.

What creators and platforms say

Kling's X posts follow the rollout. On September 28 the account wrote that Kling 4.0 was coming in October, with Flash live for Ultra Yearly subscribers. On October 15 it wrote that Kling 4.0 was fully available. On October 21 it wrote that the Kling 4.0 API was officially rolling out. The same day fal wrote that Kling 4.0 was live in its interface and agent with API access coming soon, and Higgsfield announced the model too. A creator, @Skaly__Bull, wrote on October 20 that the developer API was still marked coming soon.

Among video reviews, Oprelia AI's launch-day review says in its description that 10-bit and 4K resolutions come out later. That description carries a Kling invitation link. We have not verified the figures in these posts or videos.

Limits and open questions

Kling's pages are not consistent on 4K and 10-bit HDR, so this page promises neither. Effect Video offers 720p and 1080p, the resolutions KIE documents for the endpoint it uses, and clips of up to 15 seconds rather than the 30 the model supports. API availability is changing quickly, and the table above reflects October 22, 2026.

Most press coverage repeats Kling's and Kuaishou's own statements, and the quality claims in them come from the company. We have not compared Kling 4.0 with Kling 3.0 on identical inputs. KIE's keyframe-to-video documentation does not describe sound output, so listen to your first clip before you plan around audio.

About this page

This page was assembled from public sources: Kling's user guides, release notes and blog, Kuaishou's press release, KIE's API documentation, API providers' own pages, press coverage and posts from creators. Each claim is attributed in the text, quotations are kept to a sentence, and the References list shows every source with its type and date. Specifications were last checked on October 22, 2026.