# Kling 4.0 Flash Image to Video > Kling 4.0 Flash animates a starting image into a 720p video, with optional text prompts and durations from 3 to 20 seconds. ## Overview - **Endpoint**: `https://fal.run/kling/v4/flash/image-to-video` - **Model ID**: `kling/v4/flash/image-to-video` - **Category**: image-to-video - **Kind**: inference **Tags**: kling, v4, flash, image-to-video, audio ## Pricing Video costs **$0.094** per second at **720p**. For more details, see [fal.ai pricing](https://fal.ai/pricing). ## API Information This model can be used via our HTTP API or more conveniently via our client libraries. See the input and output schema below, as well as the usage examples. ### Input Schema The API accepts the following input parameters: - **`prompt`** (`string`, _optional_): Optional text prompt describing the shot. - Examples: "The same elements in the reference are rigid: the fictional KITO Runner 01 low-top sneaker: off-white suede overlays (#EEE9DF) on a bone-coloured finely perforated engineered mesh upper, a sage-green suede heel tab (#8FA383), a natural gum-rubber cupsole with a fine herringbone edge, tonal off-white flat laces and tonal off-white stitching; the only marking is a small debossed \"KITO\" on the sage heel tab. It is a single right shoe standing on a warm light-grey paper seamless that curves up into the background with no visible horizon line. Preserve every element exactly; the shoe and the set are frozen, only the camera moves along the keyframed trajectory: one complete, eased 360-degree orbit around the shoe like a motion-control product rig, dipping slightly lower as it passes the back and the inner side, then rising and pushing in gently to finish on a slightly higher hero three-quarter view of the same outer side it started on.\nUNSEEN SIDES must be coherent with the visible ones: the heel shows the full sage-green suede heel tab with the small debossed 'KITO' centred on it; the medial (inner) side mirrors the lateral side's off-white suede overlay layout on the perforated bone mesh; the gum cupsole wraps all the way round with the same height and herringbone edge; tonal off-white laces and stitching everywhere. The shoe is one pair-half: never a second shoe.\nLIGHT is fixed in the world: one large soft key from the upper left, so as the camera orbits the suede nap and perforations catch raking light on the far side and the gum sole glows slightly translucent when backlit; the soft contact shadow stays anchored to the floor.\nAVOID: the shoe rotating or sliding instead of the camera, sole thickness changing, extra eyelets, lace geometry re-tying itself, stripes or swoosh-like marks appearing, logo text anywhere except the heel tab, seamless edge or studio gear coming into frame, flicker, warped toe box." - **`start_image_url`** (`string`, _required_): Image to use as the first frame of the video. Flash does not take an end frame. Max file size: 30.0MB, Min width: 300px, Min height: 300px, Min aspect ratio: 0.40, Max aspect ratio: 2.50, Timeout: 20.0s - Examples: "https://v3b.fal.media/files/b/0aad8e98/IExjfxS5kaUm5jnqK5yfB_image_1.png" - **`duration`** (`integer`, _optional_): Video duration in seconds (3-20). Default value: `5` - Default: `5` - Range: `3` to `20` - Examples: 10 - **`resolution`** (`ResolutionEnum`, _optional_): Output resolution. Flash is 720p only. Default value: `"720p"` - Default: `"720p"` - Options: `"720p"` **Required Parameters Example**: ```json { "start_image_url": "https://v3b.fal.media/files/b/0aad8e98/IExjfxS5kaUm5jnqK5yfB_image_1.png" } ``` **Full Example**: ```json { "prompt": "The same elements in the reference are rigid: the fictional KITO Runner 01 low-top sneaker: off-white suede overlays (#EEE9DF) on a bone-coloured finely perforated engineered mesh upper, a sage-green suede heel tab (#8FA383), a natural gum-rubber cupsole with a fine herringbone edge, tonal off-white flat laces and tonal off-white stitching; the only marking is a small debossed \"KITO\" on the sage heel tab. It is a single right shoe standing on a warm light-grey paper seamless that curves up into the background with no visible horizon line. Preserve every element exactly; the shoe and the set are frozen, only the camera moves along the keyframed trajectory: one complete, eased 360-degree orbit around the shoe like a motion-control product rig, dipping slightly lower as it passes the back and the inner side, then rising and pushing in gently to finish on a slightly higher hero three-quarter view of the same outer side it started on.\nUNSEEN SIDES must be coherent with the visible ones: the heel shows the full sage-green suede heel tab with the small debossed 'KITO' centred on it; the medial (inner) side mirrors the lateral side's off-white suede overlay layout on the perforated bone mesh; the gum cupsole wraps all the way round with the same height and herringbone edge; tonal off-white laces and stitching everywhere. The shoe is one pair-half: never a second shoe.\nLIGHT is fixed in the world: one large soft key from the upper left, so as the camera orbits the suede nap and perforations catch raking light on the far side and the gum sole glows slightly translucent when backlit; the soft contact shadow stays anchored to the floor.\nAVOID: the shoe rotating or sliding instead of the camera, sole thickness changing, extra eyelets, lace geometry re-tying itself, stripes or swoosh-like marks appearing, logo text anywhere except the heel tab, seamless edge or studio gear coming into frame, flicker, warped toe box.", "start_image_url": "https://v3b.fal.media/files/b/0aad8e98/IExjfxS5kaUm5jnqK5yfB_image_1.png", "duration": 10, "resolution": "720p" } ``` ### Output Schema The API returns the following output format: - **`video`** (`File`, _required_): The generated video. - Examples: {"url":"https://v3b.fal.media/files/b/0ab11f9e/u_FE9bAbOG_cCzLBiqCN2_i2v.mp4","content_type":"video/mp4","file_size":16480268,"file_name":"output.mp4"} **Example Response**: ```json { "video": { "url": "https://v3b.fal.media/files/b/0ab11f9e/u_FE9bAbOG_cCzLBiqCN2_i2v.mp4", "content_type": "video/mp4", "file_size": 16480268, "file_name": "output.mp4" } } ``` ## Usage Examples ### cURL ```bash curl --request POST \ --url https://fal.run/kling/v4/flash/image-to-video \ --header "Authorization: Key $FAL_KEY" \ --header "Content-Type: application/json" \ --data '{ "start_image_url": "https://v3b.fal.media/files/b/0aad8e98/IExjfxS5kaUm5jnqK5yfB_image_1.png" }' ``` ### Python Ensure you have the Python client installed: ```bash pip install fal-client ``` Then use the API client to make requests: ```python 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( "kling/v4/flash/image-to-video", arguments={ "start_image_url": "https://v3b.fal.media/files/b/0aad8e98/IExjfxS5kaUm5jnqK5yfB_image_1.png" }, with_logs=True, on_queue_update=on_queue_update, ) print(result) ``` ### JavaScript Ensure you have the JavaScript client installed: ```bash npm install --save @fal-ai/client ``` Then use the API client to make requests: ```javascript import { fal } from "@fal-ai/client"; const result = await fal.subscribe("kling/v4/flash/image-to-video", { input: { start_image_url: "https://v3b.fal.media/files/b/0aad8e98/IExjfxS5kaUm5jnqK5yfB_image_1.png" }, logs: true, onQueueUpdate: (update) => { if (update.status === "IN_PROGRESS") { update.logs.map((log) => log.message).forEach(console.log); } }, }); console.log(result.data); console.log(result.requestId); ``` ## Deploy your own model To run your own weights, a fine-tune or a custom pipeline on the GPUs that serve this API, deploy it on fal Serverless. GPUs from H100 (80GB) to B300 (288GB), billed per second; an H100 is $4.50/h list, as low as $2.49/h. Prices, GPU specs and deploy steps: [fal Serverless](https://fal.ai/serverless.md). ## Additional Resources ### Documentation - [Model Playground](https://fal.ai/models/kling/v4/flash/image-to-video) - [API Documentation](https://fal.ai/models/kling/v4/flash/image-to-video/api) - [OpenAPI Schema](https://fal.ai/api/openapi/queue/openapi.json?endpoint_id=kling/v4/flash/image-to-video) ### fal.ai Platform - [Platform Documentation](https://fal.ai/docs/documentation) - [Python Client](https://fal.ai/docs/api-reference/client-libraries/python) - [JavaScript Client](https://fal.ai/docs/api-reference/client-libraries/javascript) ### Other agent-readable surfaces This file covers one model. To find anything else: - [Platform overview](https://fal.ai/llms.txt): Entry points and representative endpoint IDs - [Documentation index](https://fal.ai/docs/llms.txt): Every documentation page - [Full documentation text](https://fal.ai/docs/llms-full.txt): The whole documentation inlined - [Pricing](https://fal.ai/pricing.md): Model API and Serverless GPU prices - [fal Serverless](https://fal.ai/serverless.md): Deploy your own models: GPU prices, specs and steps - Any other model: `https://fal.ai/models//llms.txt`