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Alibaba Cloud Model Studio:Image-to-video: first and last frames

Last Updated:Feb 25, 2026

The Wan image-to-video model generates smooth videos from a first-frame image, a last-frame image, and an optional text prompt.

  • Video specifications: Fixed video duration (5 seconds) and custom video resolution (480P/720P/1080P).

  • Additional capabilities: Prompt rewriting and watermarking.

Quick links: API reference | Prompt guide

Getting started

Prompt

First frame

Last frame

Output video

A cute blue monster with a slightly sad expression stands in the rain. The camera slowly zooms in and stops on the moment it looks up at the sky.

image

image

Before calling the API, get an API key. Then set your API key as an environment variable. To use the SDK, install the DashScope SDK.

Python SDK

Important

Make sure your DashScope Python SDK version is at least 1.25.8 before running the code below.

If your version is too low, you may see errors such as "url error, please check url!". Install the SDK.

import os
from http import HTTPStatus
from dashscope import VideoSynthesis
import dashscope

# This URL is for the Singapore region. URLs differ by region. Get your URL: https://www.alibabacloud.com/help/en/model-studio/image-to-video-by-first-and-last-frame-api-reference
dashscope.base_http_api_url = 'https://dashscope-intl.aliyuncs.com/api/v1'
# API keys differ by region. Get your API key: https://www.alibabacloud.com/help/en/model-studio/get-api-key
api_key = os.getenv("DASHSCOPE_API_KEY", "YOUR_API_KEY")

print('please wait...')
rsp = VideoSynthesis.call(api_key=api_key,
                          model="wan2.2-kf2v-flash",
                          prompt="A cute blue monster with a slightly sad expression stands in the rain. The camera slowly zooms in and stops on the moment it looks up at the sky.",
                          first_frame_url="https://help-static-aliyun-doc.aliyuncs.com/file-manage-files/zh-CN/20260126/ixdxvt/wan-kf2v-blue-1.png",
                          last_frame_url="https://help-static-aliyun-doc.aliyuncs.com/file-manage-files/zh-CN/20260126/nhtdrc/wan-kf2v-blue-2.png",
                          duration=5,  # Fixed at 5 seconds. Do not change.
                          prompt_extend=True,
                          watermark=True)
print(rsp)
if rsp.status_code == HTTPStatus.OK:
    print("video_url:", rsp.output.video_url)
else:
    print('Failed, status_code: %s, code: %s, message: %s' % (rsp.status_code, rsp.code, rsp.message))

Java SDK

Important

Make sure your DashScope Java SDK version is at least 2.22.6 before running the code below.

If your version is too low, you may see errors such as "url error, please check url!". Install the SDK.

import com.alibaba.dashscope.aigc.videosynthesis.VideoSynthesis;
import com.alibaba.dashscope.aigc.videosynthesis.VideoSynthesisParam;
import com.alibaba.dashscope.aigc.videosynthesis.VideoSynthesisResult;
import com.alibaba.dashscope.exception.ApiException;
import com.alibaba.dashscope.exception.InputRequiredException;
import com.alibaba.dashscope.exception.NoApiKeyException;
import com.alibaba.dashscope.utils.JsonUtils;
import com.alibaba.dashscope.utils.Constants;

public class Image2Video {

    static {
        // This URL is for the Singapore region. URLs differ by region. Get your URL: https://www.alibabacloud.com/help/en/model-studio/image-to-video-by-first-and-last-frame-api-reference
        Constants.baseHttpApiUrl = "https://dashscope-intl.aliyuncs.com/api/v1";
    }

    // If you have not set an environment variable, replace the line below with: apiKey="sk-xxx"
    // API keys differ by region. Get your API key: https://www.alibabacloud.com/help/en/model-studio/get-api-key
    static String apiKey = System.getenv("DASHSCOPE_API_KEY");

    public static void image2video() throws ApiException, NoApiKeyException, InputRequiredException {
        VideoSynthesis vs = new VideoSynthesis();
        VideoSynthesisParam param =
                VideoSynthesisParam.builder()
                        .apiKey(apiKey)
                        .model("wan2.2-kf2v-flash")
                        .prompt("A cute blue monster with a slightly sad expression stands in the rain. The camera slowly zooms in and stops on the moment it looks up at the sky.")
                        .firstFrameUrl("https://help-static-aliyun-doc.aliyuncs.com/file-manage-files/zh-CN/20260126/ixdxvt/wan-kf2v-blue-1.png")
                        .lastFrameUrl("https://help-static-aliyun-doc.aliyuncs.com/file-manage-files/zh-CN/20260126/nhtdrc/wan-kf2v-blue-2.png")
                        .resolution("720P")
                        .promptExtend(true)
                        .watermark(true)
                        .build();
        System.out.println("please wait...");
        VideoSynthesisResult result = vs.call(param);
        System.out.println(JsonUtils.toJson(result));
    }

    public static void main(String[] args) {
        try {
            image2video();
        } catch (ApiException | NoApiKeyException | InputRequiredException e) {
            System.out.println(e.getMessage());
        }
        System.exit(0);
    }
}

curl

Step 1: Create a task to get the task ID

curl --location 'https://dashscope-intl.aliyuncs.com/api/v1/services/aigc/image2video/video-synthesis' \
    -H 'X-DashScope-Async: enable' \
    -H "Authorization: Bearer $DASHSCOPE_API_KEY" \
    -H 'Content-Type: application/json' \
    -d '{
    "model": "wan2.2-kf2v-flash",
    "input": {
        "first_frame_url": "https://help-static-aliyun-doc.aliyuncs.com/file-manage-files/zh-CN/20260126/ixdxvt/wan-kf2v-blue-1.png",
        "last_frame_url": "https://help-static-aliyun-doc.aliyuncs.com/file-manage-files/zh-CN/20260126/nhtdrc/wan-kf2v-blue-2.png",
        "prompt": "A cute blue monster with a slightly sad expression stands in the rain. The camera slowly zooms in and stops on the moment it looks up at the sky."
    },
    "parameters": {
        "resolution": "720P",
        "prompt_extend": true,
        "watermark": true
    }
}'

Step 2: Get the result using the task ID

Replace {task_id} with the task_id value returned by the previous API call.

curl -X GET https://dashscope-intl.aliyuncs.com/api/v1/tasks/{task_id} \
--header "Authorization: Bearer $DASHSCOPE_API_KEY"

Sample output

video_url expires after 24 hours. Download the video promptly.
{
    "request_id": "c1209113-8437-424f-a386-xxxxxx",
    "output": {
        "task_id": "966cebcd-dedc-4962-af88-xxxxxx",
        "task_status": "SUCCEEDED",
        "video_url": "https://dashscope-result-sh.oss-accelerate.aliyuncs.com/xxx.mp4?Expires=xxx",
         ...
    },
    ...
}

Availability

Supported models vary by region. Resources are isolated between regions. When calling the API, make sure your model, endpoint URL, and API key all belong to the same region. Cross-region calls will fail.

Supported models:

International

In the International deployment mode, the access point and data storage are located in the Singapore region, and model inference compute resources are dynamically scheduled worldwide, excluding Chinese Mainland.

Model

Features

Input modalities

Output video specifications

wan2.2-kf2v-flash Recommended

Video without audio

Overall stability and success rate have improved compared to model 2.1.

Text, image

Resolution options: 480P, 720P, 1080P

Video duration: 5s

Defined specifications: 30 fps, MP4 (H.264 encoding)

wan2.1-kf2v-plus

Video without audio

Text, image

Resolution options: 720P

Video duration: 5s

Defined specifications: 30 fps, MP4 (H.264 encoding)

Chinese Mainland

In the Chinese Mainland deployment mode, the access point and data storage are located in the Beijing region, and model inference compute resources are restricted to Chinese Mainland.

Model

Features

Input modalities

Output video specifications

wan2.2-kf2v-flash Recommended

Video without audio

Overall stability and success rate have improved compared to model 2.1.

Text, image

Resolution options: 480P, 720P, 1080P

Video duration: 5s

Defined specifications: 30 fps, MP4 (H.264 encoding)

wanx2.1-kf2v-plus

Video without audio

Text, image

Resolution options: 720P

Video duration: 5s

Defined specifications: 30 fps, MP4 (H.264 encoding)

Note

Sample codes in this topic apply to the Singapore region.

Core capabilities

Generate video from first and last frames

Supported models: All models.

Description: Generates smooth videos from a first-frame and a last-frame image.

Parameters:

  • first_frame_url: Required. Provide the first-frame image.

  • last_frame_url: Required. Provide the last-frame image.

  • prompt: Optional. Recommended. Controls how the video changes over time.

Prompt

First frame

Last frame

Output video

Realistic style. A curious black kitten looks up at the sky. The camera starts at eye level and gradually rises until it captures the kitten’s curious gaze from above.

首帧图像

尾帧图像

Python SDK

Make sure your DashScope Python SDK version is at least 1.25.8. Install the SDK.
import os
from http import HTTPStatus
from dashscope import VideoSynthesis
import dashscope

# This URL is for the Singapore region. URLs differ by region. Get your URL: https://www.alibabacloud.com/help/en/model-studio/image-to-video-by-first-and-last-frame-api-reference
dashscope.base_http_api_url = 'https://dashscope-intl.aliyuncs.com/api/v1'
# API keys differ by region. Get your API key: https://www.alibabacloud.com/help/en/model-studio/get-api-key
api_key = os.getenv("DASHSCOPE_API_KEY", "YOUR_API_KEY")

def sample_async_call_kf2v():
    # Asynchronous call returns a task_id
    rsp = VideoSynthesis.async_call(api_key=api_key,
                                    model="wan2.2-kf2v-flash",
                                    prompt="Realistic style. A curious black kitten looks up at the sky. The camera starts at eye level and gradually rises until it captures the kitten’s curious gaze from above.",
                                    first_frame_url="https://wanx.alicdn.com/material/20250318/first_frame.png",
                                    last_frame_url="https://wanx.alicdn.com/material/20250318/last_frame.png",
                                    duration=5,  # Fixed at 5 seconds. Do not change.
                                    prompt_extend=True,
                                    watermark=True)
    print(rsp)
    if rsp.status_code == HTTPStatus.OK:
        print("task_id: %s" % rsp.output.task_id)
    else:
        print('Failed, status_code: %s, code: %s, message: %s' % (rsp.status_code, rsp.code, rsp.message))

    # Wait for asynchronous task to complete
    rsp = VideoSynthesis.wait(task=rsp, api_key=api_key)
    print(rsp)
    if rsp.status_code == HTTPStatus.OK:
        print(rsp.output.video_url)
    else:
        print('Failed, status_code: %s, code: %s, message: %s' % (rsp.status_code, rsp.code, rsp.message))


if __name__ == '__main__':
    sample_async_call_kf2v()

Java SDK

Make sure your DashScope Java SDK version is at least 2.22.6. Install the SDK.

import com.alibaba.dashscope.aigc.videosynthesis.VideoSynthesis;
import com.alibaba.dashscope.aigc.videosynthesis.VideoSynthesisParam;
import com.alibaba.dashscope.aigc.videosynthesis.VideoSynthesisResult;
import com.alibaba.dashscope.exception.ApiException;
import com.alibaba.dashscope.exception.InputRequiredException;
import com.alibaba.dashscope.exception.NoApiKeyException;
import com.alibaba.dashscope.utils.JsonUtils;
import com.alibaba.dashscope.utils.Constants;

public class Image2Video {

    static {
        // This URL is for the Singapore region. URLs differ by region. Get your URL: https://www.alibabacloud.com/help/en/model-studio/image-to-video-by-first-and-last-frame-api-reference
        Constants.baseHttpApiUrl = "https://dashscope-intl.aliyuncs.com/api/v1";
    }

    // If you have not set an environment variable, replace the line below with: apiKey="sk-xxx"
    // API keys differ by region. Get your API key: https://www.alibabacloud.com/help/en/model-studio/get-api-key
    static String apiKey = System.getenv("DASHSCOPE_API_KEY");

    public static void image2video() throws ApiException, NoApiKeyException, InputRequiredException {
        VideoSynthesis vs = new VideoSynthesis();
        VideoSynthesisParam param =
                VideoSynthesisParam.builder()
                        .apiKey(apiKey)
                        .model("wan2.2-kf2v-flash")
                        .prompt("Realistic style. A curious black kitten looks up at the sky. The camera starts at eye level and gradually rises until it captures the kitten’s curious gaze from above.")
                        .firstFrameUrl("https://wanx.alicdn.com/material/20250318/first_frame.png")
                        .lastFrameUrl("https://wanx.alicdn.com/material/20250318/last_frame.png")
                        .resolution("720P")
                        .promptExtend(true)
                        .watermark(true)
                        .build();
        // Asynchronous call
        VideoSynthesisResult task = vs.asyncCall(param);
        System.out.println(JsonUtils.toJson(task));
        System.out.println("please wait...");

        // Get result
        VideoSynthesisResult result = vs.wait(task, apiKey);
        System.out.println(JsonUtils.toJson(result));
    }

    public static void main(String[] args) {
        try {
            image2video();
        } catch (ApiException | NoApiKeyException | InputRequiredException e) {
            System.out.println(e.getMessage());
        }
        System.exit(0);
    }
}

curl

Step 1: Create a task to get the task ID

curl --location 'https://dashscope-intl.aliyuncs.com/api/v1/services/aigc/image2video/video-synthesis' \
    -H 'X-DashScope-Async: enable' \
    -H "Authorization: Bearer $DASHSCOPE_API_KEY" \
    -H 'Content-Type: application/json' \
    -d '{
    "model": "wan2.2-kf2v-flash",
    "input": {
        "first_frame_url": "https://wanx.alicdn.com/material/20250318/first_frame.png",
        "last_frame_url": "https://wanx.alicdn.com/material/20250318/last_frame.png",
        "prompt": "Realistic style. A curious black kitten looks up at the sky. The camera starts at eye level and gradually rises until it captures the kitten’s curious gaze from above."
    },
    "parameters": {
        "resolution": "720P",
        "prompt_extend": true,
        "watermark": true
    }
}'

Step 2: Get the result using the task ID

Replace {task_id} with the task_id value returned by the previous API call.

curl -X GET https://dashscope-intl.aliyuncs.com/api/v1/tasks/{task_id} \
--header "Authorization: Bearer $DASHSCOPE_API_KEY"

Input image

  • Number of images: One first-frame image and one last-frame image.

  • Input methods: Image URL, local file path.

Method 1: Image URL (HTTP API and SDK) Recommended

  • Public URL: Supports HTTP or HTTPS. Example: https://xxxx/xxx.png.

Method 2: Local file path (SDK only)

Different programming languages (Python and Java) have different path requirements. Follow the rules below exactly.

Python SDK: Supports absolute and relative paths. Path rules:

Operating system

Input file path

Example (absolute path)

Example (relative path)

Linux / macOS

file://{absolute or relative path}

file:///home/images/test.png

file://./images/test.png

Windows

file://D:/images/test.png

file://./images/test.png

Java SDK: Supports absolute paths only. Path rules:

Operating system

Input file path

Example (absolute path)

Linux / macOS

file://{absolute path}

file:///home/images/test.png

Windows

file:///{absolute path}

file:///D:/images/test.png

Sample code: Multiple image input methods

Python SDK

import os
from http import HTTPStatus
# dashscope sdk >= 1.23.4
from dashscope import VideoSynthesis
import dashscope

dashscope.base_http_api_url = 'https://dashscope-intl.aliyuncs.com/api/v1'

# Get the DashScope API key (Model Studio API key) from the environment variable
api_key = os.getenv("DASHSCOPE_API_KEY")

# ========== Image input method (choose one) ==========
# [Method 1] Use a public image URL
first_frame_url = "https://wanx.alicdn.com/material/20250318/first_frame.png"
last_frame_url = "https://wanx.alicdn.com/material/20250318/last_frame.png"

# [Method 2] Use a local file path (file:// + file path)
# Use an absolute path
# first_frame_url = "file://" + "/path/to/your/first_frame.png"  # Linux/macOS
# last_frame_url = "file://" + "C:/path/to/your/last_frame.png"  # Windows
# Or use a relative path
# first_frame_url = "file://" + "./first_frame.png"              # Use your actual path
# last_frame_url = "file://" + "./last_frame.png"                # Use your actual path

def sample_sync_call_kf2v():
    print('please wait...')
    rsp = VideoSynthesis.call(api_key=api_key,
                              model="wan2.2-kf2v-flash",
                              prompt="Realistic style, a small black cat looks up at the sky curiously, the camera gradually rises from eye level, and finally captures its curious gaze from a top-down view.",
                              first_frame_url=first_frame_url,
                              last_frame_url=last_frame_url,
                              resolution="720P",
                              prompt_extend=True)
    print(rsp)
    if rsp.status_code == HTTPStatus.OK:
        print(rsp.output.video_url)
    else:
        print('Failed, status_code: %s, code: %s, message: %s' %
              (rsp.status_code, rsp.code, rsp.message))


if __name__ == '__main__':
    sample_sync_call_kf2v()

Java SDK

// Copyright (c) Alibaba, Inc. and its affiliates.

// dashscope sdk >= 2.20.1
import com.alibaba.dashscope.aigc.videosynthesis.VideoSynthesis;
import com.alibaba.dashscope.aigc.videosynthesis.VideoSynthesisParam;
import com.alibaba.dashscope.aigc.videosynthesis.VideoSynthesisResult;
import com.alibaba.dashscope.exception.ApiException;
import com.alibaba.dashscope.exception.InputRequiredException;
import com.alibaba.dashscope.exception.NoApiKeyException;
import com.alibaba.dashscope.utils.Constants;
import com.alibaba.dashscope.utils.JsonUtils;

import java.util.HashMap;
import java.util.Map;


public class Kf2vSyncIntl {

    static {
        Constants.baseHttpApiUrl = "https://dashscope-intl.aliyuncs.com/api/v1";
    }

    // Get the DashScope API key (Model Studio API key) from the environment variable
    static String apiKey = System.getenv("DASHSCOPE_API_KEY");

    /**
     * Image input method (choose one):
     *
     * [Method 1] Public URL
     */
    static String firstFrameUrl = "https://wanx.alicdn.com/material/20250318/first_frame.png";
    static String lastFrameUrl = "https://wanx.alicdn.com/material/20250318/last_frame.png";

     /**
     * [Method 2] Local file path (file:// + absolute path or file:/// + absolute path)
     */
    // static String firstFrameUrl = "file://" + "/your/path/to/first_frame.png";  // Linux/macOS
    // static String lastFrameUrl = "file:///" + "C:/path/to/your/img.png";        // Windows

    public static void syncCall() {

        Map<String, Object> parameters = new HashMap<>();
        parameters.put("prompt_extend", true);
        parameters.put("resolution", "720P");

        VideoSynthesis videoSynthesis = new VideoSynthesis();
        VideoSynthesisParam param =
                VideoSynthesisParam.builder()
                        .apiKey(apiKey)
                        .model("wan2.2-kf2v-flash")
                        .prompt("Realistic style, a small black cat looks up at the sky curiously, the camera gradually rises from eye level, and finally captures its curious gaze from a top-down view.")
                        .firstFrameUrl(firstFrameUrl)
                        .lastFrameUrl(lastFrameUrl)
                        .parameters(parameters)
                        .build();
        VideoSynthesisResult result = null;
        try {
            System.out.println("---sync call, please wait a moment----");
            result = videoSynthesis.call(param);
        } catch (ApiException | NoApiKeyException e){
            throw new RuntimeException(e.getMessage());
        } catch (InputRequiredException e) {
            throw new RuntimeException(e);
        }
        System.out.println(JsonUtils.toJson(result));
    }

    public static void main(String[] args) {
        syncCall();
    }
}

Output video

  • Number of videos: One.

  • Specifications: Specifications vary by model. See Video specifications.

  • URL expiration: 24 hours.

  • Dimensions: Determined by the first-frame image and the resolution setting.

    • The model preserves the aspect ratio of the first-frame image and scales the total pixel count close to the target. Because of encoding requirements, the output width and height must be divisible by 16. The model adjusts dimensions automatically.

    • For example: Input image is 750×1000 (aspect ratio 3:4 = 0.75). Set resolution = "720P" (target pixel count ≈ 920,000). Output may be 816 × 1104 (aspect ratio ≈ 0.739, pixel count ≈ 900,000), with both dimensions divisible by 16.

Billing and rate limiting

  • For free quota and pricing details, see Model invocation pricing.

  • For model rate limiting, see Wan series.

  • Billing details:

    • Input is free. Output is billed. Billing is based on the number of successful video seconds generated.

    • Failed or erroneous calls incur no charges and do not consume your free trial quota.

    • Image-to-video also supports savings plans.

API reference

Image-to-video - first and last frames - API reference

FAQ

Q: How do I generate a video with a specific aspect ratio (such as 3:4)?

A: The API does not support specifying aspect ratios directly. You can only set the video resolution using the resolution parameter.

The resolution parameter controls total pixel count, not strict aspect ratio. The model prioritizes preserving the original aspect ratio of the first-frame image (first_frame_url) and makes minor adjustments to meet encoding requirements (width and height must be multiples of 16). To get a video close to 3:4, upload a first-frame image with a 3:4 aspect ratio.

For example: Input image is 750×1000 (aspect ratio 3:4 = 0.75). Set resolution = "720P" (target pixel count ≈ 920,000). Output may be 816 × 1104 (aspect ratio ≈ 0.739, pixel count ≈ 900,000), with both dimensions divisible by 16.

Q: Why do I get a “url error, please check url!” error when running the SDK code?

A: Make sure:

  • Your DashScope Python SDK version is at least 1.25.8.

  • Your DashScope Java SDK version is at least 2.22.6.

If your version is too low, you may see the "url error, please check url!" error. Upgrade the SDK.