Kling v2.1

High-quality image-to-video generation from Kuaishou AI Team, supporting 720p and 1080p resolution at 24fps.

Property	Value
Model ID	`kwaivgi/kling-v2.1`
Provider	Replicate
Type	Video generation (image-to-video)

Basic Usage

Kling v2.1 is an image-to-video model that requires a starting image:

import { compose, generateVideo, videoModel } from "@synthome/sdk";

const execution = await compose(
  generateVideo({
    model: videoModel("kwaivgi/kling-v2.1", "replicate"),
    prompt: "The woman turns and smiles at the camera",
    startImage: "https://example.com/portrait.jpg",
  }),
).execute();

Options

Option	Type	Default	Description
`prompt`	`string`	required	Text description of the video motion
`startImage`	`string`	required	First frame image URL
`resolution`	`"720p" \| "1080p"`	-	Output resolution (maps to standard/pro mode)
`duration`	`5 \| 10`	-	Video duration in seconds
`endImage`	`string`	-	Target end frame image URL (1080p/pro only)

Resolution Modes

Kling v2.1 supports two quality modes that map to resolution:

Resolution	Mode	Frame Rate	Use Case
`720p`	Standard	24fps	Fast generation
`1080p`	Pro	24fps	High-quality output

// Standard mode (720p)
generateVideo({
  model: videoModel("kwaivgi/kling-v2.1", "replicate"),
  prompt: "A gentle breeze moves the leaves",
  startImage: "https://example.com/tree.jpg",
  resolution: "720p",
});

// Pro mode (1080p)
generateVideo({
  model: videoModel("kwaivgi/kling-v2.1", "replicate"),
  prompt: "A gentle breeze moves the leaves",
  startImage: "https://example.com/tree.jpg",
  resolution: "1080p",
});

Duration

Generate 5 or 10 second videos:

generateVideo({
  model: videoModel("kwaivgi/kling-v2.1", "replicate"),
  prompt: "The dancer spins gracefully",
  startImage: "https://example.com/dancer.jpg",
  duration: 10, // 10 second video
});

End Frame Control

In pro mode (1080p), you can specify a target end frame:

generateVideo({
  model: videoModel("kwaivgi/kling-v2.1", "replicate"),
  prompt: "The scene transitions smoothly",
  startImage: "https://example.com/scene-start.jpg",
  endImage: "https://example.com/scene-end.jpg",
  resolution: "1080p", // Required for end frame
});

Examples

Portrait Animation

generateVideo({
  model: videoModel("kwaivgi/kling-v2.1", "replicate"),
  prompt: "The person looks up and smiles warmly",
  startImage: "https://example.com/portrait.jpg",
  resolution: "1080p",
  duration: 5,
});

Product Video

generateVideo({
  model: videoModel("kwaivgi/kling-v2.1", "replicate"),
  prompt: "The product rotates slowly, highlighting its features",
  startImage: "https://example.com/product.png",
  resolution: "720p",
  duration: 5,
});

Scene Transition

generateVideo({
  model: videoModel("kwaivgi/kling-v2.1", "replicate"),
  prompt: "Day transitions to night with city lights appearing",
  startImage: "https://example.com/city-day.jpg",
  endImage: "https://example.com/city-night.jpg",
  resolution: "1080p",
  duration: 10,
});

Best Practices

Start Image Quality: Use high-resolution, clear images for best results
Descriptive Prompts: Include motion descriptions like "slowly", "gracefully", "turns"
Duration Choice: Use 5s for simple motions, 10s for complex transformations
End Frame: Only available in pro mode (1080p) - great for controlled transitions

Kling v2.1

On this page