3 to 20 seconds per run
Set the duration anywhere from 3 to 20 seconds in a single generation, long enough for a full social clip or ad cut without stitching.
New · Opened to everyone on November 4, 2026
KL AI 4.0 Flash
KL AI 4.0 Flash is the fast, lower-cost member of the 4.0 video generation. It turns a prompt, a single first frame or a set of references into 3 to 20 second clips at 720p, and costs about 40% less per second than the full KL AI 4.0.
What is KL AI 4.0 Flash?
Flash belongs to the same 4.0 generation as the full KL AI 4.0 and shares its prompt budget, reference limits and request types. It is a speed and price tier: it stops at 720p and 20 seconds and drops multi-keyframe control, in exchange for faster turnaround and a lower rate per second. That makes it a drafting and volume tool rather than a mastering tool.
September 28, 2026
The 4.0 generation is announced. Flash goes out first, as early access for top-tier annual subscribers only.
October 28, 2026
The full KL AI 4.0 becomes generally available through the API: up to 30 seconds, 720p and 1080p, up to 10 keyframes.
November 4, 2026
Flash opens to every user and gets a public API with a published per-second price. The waitlist and the annual-plan requirement end.
What 4.0 Flash can do
720p output
Flash renders at 720p in 8-bit SDR. That suits feeds, vertical ad slots and edit previews; there is no 1080p or 4K tier for Flash.
Text, first frame or references
Start from a prompt, from one first-frame image, or from an Omni reference task with up to 10 images and 5 videos, 15 inputs in total.
Long prompts and wide framing
Prompts can run to 26,000 English characters, and the aspect ratio can be 21:9 or adaptive in addition to the usual 16:9, 9:16 and 1:1.
KL AI 4.0 Flash vs KL AI 4.0
The two share a generation, a prompt budget and a reference budget. The differences are length, resolution, keyframes and price.
| Feature | KL AI 4.0 Flash | KL AI 4.0 |
|---|---|---|
| Clip length | 3–20 seconds | 3–30 seconds |
| Resolution | 720p only, 8-bit SDR | 720p or 1080p; 10-bit 4K announced |
| Image-to-video control | One first-frame image | Up to 10 keyframes along the timeline |
| References | Up to 10 images, 5 videos, 15 inputs | Same limits, plus direct voice references |
| Price per second at 720p | About 40% lower | Baseline; 1080p costs about 50% more than 720p |
Prices compare the developer's published API rates for runs without input video. Credits on kling3.org are shown in the studio before you generate.
Which one fits your project?
Pick 4.0 Flash when
- Your final video is 720p anyway, such as social feeds, short ads or previews.
- You are testing many prompt variations and care most about cost per draft.
- Your shot does not need to land on a specific last frame.
Pick the full KL AI 4.0 when
- You need a 1080p master or a clip longer than 20 seconds.
- The shot has to hit set frames, so keyframe control matters.
- You want to make the video today: it is already in the KL AI studio.
Start with the 4.0 generation today
Flash and the full model read prompts the same way, so you can write and refine your 4.0 prompts in the studio right now.
1
Open KL AI 4.0 in the studio
The button on this page opens the video studio with KL AI 4.0 selected. Sign in to see your credit balance.
2
Describe the shot and set the length
Write the subject, action, camera move and mood, add reference images if you have them, and pick 3 to 30 seconds at 720p or 1080p.
3
Draft at 720p, finish at 1080p
Short 720p drafts keep costs low, which is the Flash way of working. Once the motion is right, render the final take at 1080p.
KL AI 4.0 Flash FAQ
What is KL AI 4.0 Flash?
It is the fast, lower-cost tier of the 4.0 video generation. It makes 3 to 20 second clips at 720p from text, a single first frame or Omni references, at about 40% less per second than the full KL AI 4.0.
Who can use 4.0 Flash?
Since November 4, 2026, anyone. Before that, from September 28, it was limited to top-tier annual subscribers as early access.
Does 4.0 Flash support 1080p or keyframes?
No. Flash outputs 720p only and its image-to-video mode takes a single first frame. For 1080p, clips up to 30 seconds or up to 10 keyframes, use the full KL AI 4.0.
How much cheaper is Flash than KL AI 4.0?
On the developer's API rate card, a second of 720p Flash output without input video costs about 40% less than the same second from the full model. With input video, both tiers bill on a longer total duration, so check the full cost before relying on the lower rate.
Is Flash lower quality than the full model?
It is the same generation with the same reference and prompt limits. What it gives up is resolution, length and keyframe control, so it fits drafts and 720p delivery better than final masters.
Make your first 4.0 video
The full KL AI 4.0 is ready in the studio: up to 30 seconds, 720p or 1080p, from a prompt or your own images.