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Endpoint: POST https://fal.run/fal-ai/kling-video/o1/image-to-video Endpoint ID: fal-ai/kling-video/o1/image-to-video

Try it in the Playground

Run this model interactively with your own prompts.

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Quick Start

import fal_client

def on_queue_update(update):
    if isinstance(update, fal_client.InProgress):
        for log in update.logs:
           print(log["message"])

result = fal_client.subscribe(
    "fal-ai/kling-video/o1/image-to-video",
    arguments={
        "prompt": "Create a magical timelapse transition. The snow melts rapidly to reveal green grass, and the tree branches burst into bloom with pink flowers in real-time. The lighting shifts from cold winter light to warm spring sunshine. The camera pushes in slowly towards the tree. Disney-style magical transformation, cinematic, 8k.",
        "start_image_url": "https://v3b.fal.media/files/b/rabbit/NaslJIC7F2WodS6DFZRRJ.png"
    },
    with_logs=True,
    on_queue_update=on_queue_update,
)
print(result)
Kuaishou’s Kling O1 delivers first-frame-last-frame video generation at $0.112 per second, animating precise transitions between two keyframes. Trading broad creative freedom for exact endpoint control, this specialized variant handles timelapse transformations, morphing sequences, and narrative scene transitions where both start and end states matter. Built for motion designers, creative studios, and developers who need deterministic video outputs rather than open-ended generation. Built for: Timelapse animations | Product transformation sequences | Narrative scene transitions

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Dual-Keyframe Control Architecture

Kling O1’s dual-keyframe approach inverts the standard image-to-video workflow by accepting both start and end images as constraints, then synthesizing the motion path between them. Where traditional image-to-video models extrapolate freely from a single frame, this variant interpolates along a defined trajectory while respecting prompt-driven style guidance. What this means for you:
  • Deterministic endpoints: Generate 5 or 10-second videos where both opening and closing frames match your exact specifications, critical for brand-consistent sequences or narrative continuity
  • Controlled transformation arcs: Animate seasonal changes, product evolutions, or character state transitions with predictable motion paths rather than AI-improvised endings
  • Prompt-guided interpolation: Reference start and end frames via @Image1 and @Image2 in prompts to direct style, camera movement, and scene dynamics during the transition
  • Flexible duration options: Choose between 5-second (0.56)or10−second(0.56) or 10-second (1.12) outputs to match pacing requirements for social media clips or longer editorial sequences

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Performance Scaling

Kling O1 operates within Kuaishou’s broader Kling Video ecosystem, prioritizing frame-accurate transitions over generation speed.
MetricResultContext
Duration Options5s or 10sConfigurable via duration parameter
Cost per Video0.56(5s)or0.56 (5s) or 1.12 (10s)Based on $0.112 per second rate
Input RequirementsStart + end frame (both required)Min 300px dimensions, 0.40-2.50 aspect ratio, 10MB max per image
Output FormatMP4 videoSingle video file with synthesized motion path

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Technical Specifications

SpecDetails
ArchitectureKling O1
Input FormatsStart image (required), end image (required), text prompt with frame references
Output FormatsMP4 video
Duration Options5 seconds or 10 seconds
Prompt SyntaxUse @Image1 and @Image2 to reference uploaded keyframes in prompts
LicenseCommercial use via fal partnership
API Documentation

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How It Stacks Up

Kling Video Image to Video (v2.5-turbo) - Kling O1 specializes in dual-keyframe interpolation for transformation sequences where endpoint precision matters, making it ideal for timelapse effects and morphing animations. Kling Video v2.5-turbo emphasizes single-frame extrapolation with faster generation speeds for open-ended creative exploration. Kling 2.0 Master Image to Video - Kling O1 trades generation flexibility for endpoint accuracy, constraining motion paths between two defined frames at a specialized price point. Kling 2.0 Master prioritizes maximum quality single-frame animation for premium production workflows requiring cinematic motion without endpoint constraints.

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Capabilities

  • Text prompt input
  • Duration control

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API Reference

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Input Schema

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prompt
string
required
Use @Image1 to reference the start frame, @Image2 to reference the end frame.
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start_image_url
string
required
Image to use as the first frame of the video.Max file size: 10.0MB, Min width: 300px, Min height: 300px, Min aspect ratio: 0.40, Max aspect ratio: 2.50, Timeout: 20.0s
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end_image_url
string
Image to use as the last frame of the video.
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duration
DurationEnum
default:"5"
Video duration in seconds. Default value: "5"Possible values: 3, 4, 5, 6, 7, 8, 9, 10

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Output Schema

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video
File
required
The generated video.

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Input Example

{
  "prompt": "Create a magical timelapse transition. The snow melts rapidly to reveal green grass, and the tree branches burst into bloom with pink flowers in real-time. The lighting shifts from cold winter light to warm spring sunshine. The camera pushes in slowly towards the tree. Disney-style magical transformation, cinematic, 8k.",
  "start_image_url": "https://v3b.fal.media/files/b/rabbit/NaslJIC7F2WodS6DFZRRJ.png",
  "end_image_url": "https://v3b.fal.media/files/b/tiger/BwHi22qoQnqaTNMMhe533.png",
  "duration": "5"
}

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Output Example

{
  "video": {
    "content_type": "video/mp4",
    "file_name": "output.mp4",
    "file_size": 27588984,
    "url": "https://v3b.fal.media/files/b/koala/knryyyGF3ZVyMMrGr77CL_output.mp4"
  }
}

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Limitations

  • duration restricted to: 3, 4, 5, 6, 7, 8, 9, 10