> For clean Markdown of any page, append .md to the page URL. > For a complete documentation index, see https://docs.empiriolabs.ai/llms.txt. > For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.empiriolabs.ai/_mcp/server. # Kling 4.0 > Makes 3 to 30 second clips at 720p or 1080p with native audio from text, first, middle and last frames, reference images and videos, or a video to edit. ![Kling 4.0](https://media.empiriolabs.ai/model-logos/kling-4-0.png) [Kling AI](/providers/kling) · Video Generation `POST /v1/videos/generations` Makes 3 to 30 second clips at 720p or 1080p with native audio from text, first, middle and last frames, reference images and videos, or a video to edit. ## At a glance | Field | Value | | ------------------- | --------------------------------------------------------------- | | Model id | `kling-4-0` | | Model release date | 2026-10-15 | | Input modalities | Text, Image, Video | | Output modalities | Video | | Context window | - | | Weight precision | - | | Features | video_generation, text_to_video, image_to_video, audio, editing | | Native inference | No | | New | Yes | | Supported endpoints | `POST /v1/videos/generations` | | Alternate model ids | `kling-4.0`, `kling/kling-4-0` | ## Pricing | Charge | Spec | Rate | | ----------------- | ---------------------------------------------------------- | ------- | | Standard 720p | per second | \$0.157 | | Standard 1080p | per second | \$0.235 | | Video input 720p | per second of input plus output, at least twice the output | \$0.094 | | Video input 1080p | per second of input plus output, at least twice the output | \$0.141 | ## Example request ```bash curl https://api.empiriolabs.ai/v1/videos/generations \ -H 'Authorization: Bearer $EMPIRIOLABS_API_KEY' \ -H 'Content-Type: application/json' \ -d '{"model": "kling-4-0", "prompt": "sunrise over the ocean", "duration": 6}' ``` ## Parameters | Parameter | Type | Required | Default | Description | | ------------------ | ------ | -------- | --------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `prompt` | string | yes | - | Scene description, up to 26,000 English or 11,000 non-English characters. Refer to images as @image_1, @image_2 and videos as @video_1 in the order they are supplied. | | `resolution` | enum | no | `"1080p"` | Output resolution. 1080p is billed at a higher per-second rate than 720p. · Allowed: `720p`, `1080p` | | `aspect_ratio` | enum | no | `"16:9"` | Output aspect ratio for text-to-video and reference images. A first, middle or last frame, or a video to edit, sets the aspect ratio instead. · Allowed: `16:9`, `9:16`, `1:1`, `21:9` | | `duration` | number | no | `5` | Clip length in seconds, whole numbers only. A video edit keeps the length of the video it edits. · Range: 3 – 30 | | `image` | string | no | - | First frame image URL. The video starts on this image. | | `image_end` | string | no | - | Last frame image URL. The video ends on this image. | | `middle_images` | string | no | - | Keyframe image URLs between the first and last frame, in order, as a list or comma-separated. | | `reference_images` | string | no | - | Reference image URLs for characters, objects, scenes or style, as a list or comma-separated. Up to 10 images in total across all image inputs. | | `video` | string | no | - | Video URL to edit, 3 to 30 seconds. The result keeps its length and aspect ratio, and bills at the video input rate. | | `reference_videos` | string | no | - | Reference video URLs for motion, camera work or style, 3 to 30 seconds each, as a list or comma-separated. Up to 5 videos in total. Bills at the video input rate. | ## Notes Generates 3 to 30 second clips at 24 fps in 720p or 1080p, each with a native stereo audio track. **Inputs** * Text to video: prompt only. * Keyframes: a first frame (`image`), middle frames (`middle_images`) and a last frame (`image_end`). The video follows the first frame's aspect ratio. * Reference images (`reference_images`): characters, objects, scenes or style to use. * Reference videos (`reference_videos`): motion, camera work or style to follow, 3 to 30 seconds each. * Video edit (`video`): a video to edit, 3 to 30 seconds. The result keeps its length and aspect ratio. * Up to 10 images and 5 videos per request. In the prompt, refer to images as @image_1, @image_2 (first frame, middle frames, last frame, then references) and to videos as @video_1, @video_2 (the video to edit first). **In the Playground** One attached image is the first frame, two are the first and last frames, and three or more are references. The first attached video is the one edited; any others are references. **Media limits** * Images: JPG or PNG, at least 300 px, aspect ratio between 2:5 and 5:2, up to 30 MB. * Videos: MP4 or MOV, 3 to 30 seconds, 700 to 4553 px per side, up to 300 MB. **Billing** * Without a video input: billed per second of the generated clip at the resolution you request. * With a video input (a video to edit or a reference video): billed at the video input rate on twice the length of the generated clip, or on the input plus the output when the input is longer. --- *Machine-readable schema:* `GET https://api.empiriolabs.ai/v1/models/kling-4-0`.