KuaishouSlowUltra

Kling O3 4K Video to Video Edit

Kling O3 native 4K video editing via Fal.AI. Edits an existing video (cited as @Video1) from a text instruction — change the environment, restyle the scene, or swap a subject for an element image (@Element1) — keeping the original motion and timing, and outputs native 4K directly. Input clips of 3-15 seconds.

12230 credits

per 5s 4K clip — billed per second of output (= measured input clip length), 977/s

Text-instructed editing of an existing clip — environment, style, or subject swaps

Keeps the original motion, timing, and (optionally) audio

Native 4K output in one step — no upscaling pass

Element references (@Element1) for subject replacement and style images (@Image1)

Billed by the measured length of the input clip

Run it right now

Test this model instantly in the Console Playground — no code required

Use with AI Assistant

Copy usage instructions for Claude, ChatGPT, or other AI

llms.txtllms.txt ↗

Quick Start

curl -X POST "https://api.core.today/v1/predictions" \
  -H "Content-Type: application/json" \
  -H "X-API-Key: cdt_your_api_key" \
  -d '{
  "model": "fal-ai/kling-video/o3/4k/video-to-video/edit",
  "input": {
    "prompt": "Change environment to be fully snow as @Image1. Replace animal with @Element1",
    "video_url": "https://storage.googleapis.com/falserverless/example_inputs/kling-o3/pro-v2v-edit/video_reference.mp4",
    "elements": [
      {
        "frontal_image_url": "https://storage.googleapis.com/falserverless/example_inputs/kling-o3/pro-v2v-edit/element1_front.png",
        "reference_image_urls": [
          "https://storage.googleapis.com/falserverless/example_inputs/kling-o3/pro-v2v-edit/element1_reference1.png"
        ]
      }
    ],
    "image_urls": [
      "https://storage.googleapis.com/falserverless/example_inputs/kling-o3/pro-v2v-edit/image_url1.jpg"
    ]
  }
}'

Parameters

Parameter	Type	Required	Default	Description
`prompt`	string	Yes	-	Edit instruction. Refer to the input video as @Video1, element images as @Element1, and style images as @Image1. Max 2500 characters
`video_url`	string	Yes	-	Video to edit. .mp4/.mov, 3-15 seconds, 720-3840px, 23-60 fps, max 200MB. The output keeps this clip's length and is billed by its measured duration
`elements`	array	No	-	Characters/objects to include, each with a frontal_image_url and 1-3 reference_image_urls; cited as @Element1, @Element2. Elements plus image_urls total at most 4
`image_urls`	array	No	-	Style/appearance reference images, cited as @Image1, @Image2. Elements plus image_urls total at most 4
`keep_audio`	boolean	No	true	Keep the original audio from the input video
`enable_safety_checker`	boolean	No	true	Enable the safety checker

How to Provide File Input

There are 3 ways to provide files for the video_urlimage_urls parameters:

Recommended

Image URL

Pass a publicly accessible URL directly. With the Storage API (POST /v1/files/upload-url) the file uploads straight to S3 (50MB per file) and you pass the returned file_url.

{
  "model": "fal-ai/kling-video/o3/4k/video-to-video/edit",
  "input": {
    "prompt": "your prompt here",
    "video_url": "https://example.com/image.jpg"
  }
}

Direct Upload (Multipart)

Attach files directly to POST /v1/predictions/upload. No separate upload step, but the bytes pass through the API server so the whole request is capped at 10MB.

curl -X POST "https://api.core.today/v1/predictions/upload" \
  -H "X-API-Key: cdt_your_api_key" \
  -F "model=fal-ai/kling-video/o3/4k/video-to-video/edit" \
  -F 'input={"prompt":"your prompt here"}' \
  -F "file:video_url=@your_file.png"

See the File Upload docs for more upload methods including Presigned URLs.

Common Parameters

Common parameters used when calling POST /v1/predictions.

Parameter	Type	Required	Default	Description
`model`	string	Yes	-	Model identifier
`input`	object	Yes	-	Object containing the model-specific parameters from the table above
`output_folder`	string	No	-	Folder path for output files (max 256 chars, '..' not allowed)
`webhook_url`	string	No	-	Webhook URL to call on completion
`is_public`	boolean	No	false	If true, output files are also available via permanent public URLs

Examples

Snow Scene with Subject Swap

Turn the environment to snow and replace the animal with an element

curl -X POST "https://api.core.today/v1/predictions" \
  -H "Content-Type: application/json" \
  -H "X-API-Key: cdt_your_api_key" \
  -d '{
  "model": "fal-ai/kling-video/o3/4k/video-to-video/edit",
  "input": {
    "prompt": "Change environment to be fully snow as @Image1. Replace animal with @Element1",
    "video_url": "https://storage.googleapis.com/falserverless/example_inputs/kling-o3/pro-v2v-edit/video_reference.mp4",
    "elements": [
      {
        "frontal_image_url": "https://storage.googleapis.com/falserverless/example_inputs/kling-o3/pro-v2v-edit/element1_front.png",
        "reference_image_urls": [
          "https://storage.googleapis.com/falserverless/example_inputs/kling-o3/pro-v2v-edit/element1_reference1.png"
        ]
      }
    ],
    "image_urls": [
      "https://storage.googleapis.com/falserverless/example_inputs/kling-o3/pro-v2v-edit/image_url1.jpg"
    ]
  }
}'