What is Kling 4.0 Flash?
Kling 4.0 Flash is the fast model in Kuaishou's Kling 4.0 lineup, opened for early access to a limited group of users on September 28, 2026. It is not yet callable on Unifically. We will open it here once Kuaishou's API serves it, and every spec on this page comes from the release and will be re-verified against the callable API on day one.
Flash is built on Kling 4.0 and carries a subset of its features. It generates 3 to 20 second videos at 720p from a prompt, a start image, or Omni Reference assets. It trades the full model's 4K output, 30-second length, and keyframe control for faster generation at a lower cost, which makes it the Kling 4.0 model for drafts and frequent creation.
Key features of Kling 4.0 Flash
- 3 to 20 seconds per generation. Longer than any Kling 3.0 model, with room for a complete social video in one pass.
- Three input modes. Text-to-video, image-to-video from a start image, and Omni Reference for building a scene from character, location, and object references.
- Omni Reference on the fast model. Combine portraits and a location shot, and the people and place carry into the generated video.
- 720p output. One fixed resolution in 8-bit SDR, which keeps the model fast and cheap per second.
- Built for volume. Positioned for frequent creation where turnaround and cost matter more than maximum resolution.
Best for
Prompt drafts
Test a scene idea at 720p before paying for a full Kling 4.0 render.
Social video
Up to 20 seconds covers a full Reel or Short in one generation.
Character scenes from references
Omni Reference keeps the faces and location from your reference photos.
High-volume pipelines
Speed and cost matter more than resolution when you generate many videos a day.
Use cases
Run a batch of short concept drafts for a campaign, pick the strongest one, then re-render it on the full Kling 4.0 model at 1080p or 4K. Feed two portraits and a location photo into Omni Reference to produce a short scene with the same people in the same place. Animate a product still or a key frame into a 20-second vertical video for social feeds. And for apps that generate video on demand, Flash is the model to default to when the output is watched on a phone at 720p anyway.
Limitations
Flash outputs 720p only, in 8-bit SDR, with no 1080p, 4K, or HDR option. It does not support first and last frame control or multi-keyframe input; those stay on the full Kling 4.0 model. The 20-second ceiling sits below the full model's 30 seconds. Kuaishou has published no generation times or prices for Flash yet, so the speed and cost gap against Kling 4.0 is not measured. Access is limited early access in the Kling app as of October 1, 2026, and the model is not on Kuaishou's developer API.
Kling 4.0 Flash vs Kling 4.0
Both come from the same Kling 4.0 release. The full model generates 3 to 30 seconds at 720p, 1080p, or 4K, with first and last frames, up to 10 keyframes, stereo audio, and up to 15 reference assets. Flash covers 3 to 20 seconds at 720p with text-to-video, image-to-video, and Omni Reference only. Use Flash to iterate fast and keep cost down, and move to Kling 4.0 for the final render when you need resolution, length, or keyframe control.
Kling 4.0 Flash vs Kling 3.0 Turbo
Kling 3.0 Turbo is the speed model of the previous generation and the one to use on Unifically today. It runs 3 to 15 seconds at 720p Standard or 1080p Pro, text-to-video or image-to-video, from $0.066 per second, without native audio or multi-reference input. Flash goes to 20 seconds and adds Omni Reference, so the people and places from your photos carry into the video, but it stops at 720p. When Flash launches here, it replaces Turbo for reference-driven drafts; Turbo keeps the edge when you need a fast 1080p render.
How to get access to Kling 4.0 Flash
Kling 4.0 Flash opened to a limited group of users on September 28, 2026, as part of the Kling 4.0 lineup, and the full Kling 4.0 model launches in October 2026. Access today runs through the Kling app; neither model is on Kuaishou's developer API yet. When the API opens, Kling 4.0 Flash will appear on Unifically with a browser playground on this page, a REST endpoint under the same API key as every other model, and pay-per-second billing from one balance.
What Kling 4.0 Flash can do
Two portraits and a place become one scene
Omni Reference on the fast model: a portrait of a man, a portrait of a woman, and a photo of a clifftop become a 15-second scene of the two meeting on the cliff edge, laughing and holding hands. Both faces and the landscape match the references.
Fast martial arts from one reference still
One reference still of two karate fighters in a wooden dojo becomes a fast exchange of punches, kicks, and a leaping strike, with the gi, belts, and warm window light holding through the action.
FAQs
People also ask
Kling 4.0 Flash is the fast, lower-cost model in Kuaishou's Kling 4.0 lineup. It generates 3 to 20 second videos at 720p from text, a start image, or a set of Omni Reference assets, and is built for frequent, high-volume creation.
Kling 4.0 Flash opened to a limited group of users in the Kling app for early access on September 28, 2026. The full Kling 4.0 model launches in October 2026.
Not yet. Kuaishou's developer API does not serve Kling 4.0 Flash so far, and neither does Unifically. We will open it here once the API is live, and this page will get the playground, callable parameters, and pricing at that point.
3 to 20 seconds per generation, 5 seconds more than Kling 3.0's 15-second ceiling. The full Kling 4.0 model goes to 30 seconds.
720p only, in 8-bit SDR. For 1080p or 4K output, use the full Kling 4.0 model.
No. Flash covers text-to-video, image-to-video from a start image, and Omni Reference. First and last frame control and multi-keyframe input are only on the full Kling 4.0 model.
Use Flash for drafts, social video, and volume work where 720p is enough and speed matters. Use Kling 4.0 when you need 1080p or 4K, videos longer than 20 seconds, or keyframe control.
Kuaishou is rolling Kling 4.0 Flash out to a limited group of users inside the Kling app; signing in there shows whether your account has it. API access is not open yet. Once it is, Kling 4.0 Flash will be callable on Unifically with the same API key and balance as every other model.
Kuaishou has not published Kling 4.0 Flash prices yet, only that it is the lower-cost Kling 4.0 model. Unifically will bill it per second of output with no subscription and post the rate on this page at launch. For comparison, Kling 3.0 Turbo on Unifically starts at $0.066 per second.
There is no free Kling 4.0 Flash API. Every new Unifically account gets $0.50 of free balance with no subscription, usable in the playground on Kling 3.0 and other live models today, and on Kling 4.0 Flash once it launches here.
