Try LTX 2.3 Fast: Image to Video in the Workbench
Run this model interactively, tune parameters, and compare outputs.
ltx-2-3-fast-image-to-video
LTX 2.3 Fast (Image to Video) is the speed-optimized variant of Lightricks LTX-2.3 on fal, animating a starting image into video with synchronized native audio at lower latency and cost than the standard tier. An optional end image can be supplied to generate a transition between the start and end frames. It supports 1080p, 1440p, and 2160p output at 24/25/48/50 FPS.
The fast model supports clip durations from 6 up to 20 seconds; durations longer than 10 seconds (12, 14, 16, 18, 20) require 25 FPS and 1080p resolution. Input images may be PNG, JPEG, WebP, AVIF, or HEIF.
Example request
- Sync
- Async
- Async with SSE
This blocks until the video is ready (typically 5-15 minutes). Prefer Async or Async with SSE for anything beyond quick experimentation.See the video generation reference for more details.
- Minimal
- Basic parameters
- All parameters
Fetch model details
The models endpoint returns the full model object, including itsjson_request_schema.
Request parameters
Required parameters
| Field | Type | Default | Description |
|---|---|---|---|
prompt | string | — | The prompt to generate the video from. |
input_image | string | — | URL of the image to generate the video from. Supports PNG, JPEG, WebP, AVIF, and HEIF formats. Format: uri. |
Optional parameters
| Field | Type | Default | Description |
|---|---|---|---|
last_frame_image | string | — | The URL of the end image to use for the generated video. When provided, generates a transition video between start and end frames. Format: uri. |
duration | integer | 6 | The duration of the generated video in seconds. The fast model supports 6-20 seconds. Durations longer than 10 seconds (12, 14, 16, 18, 20) are only supported with 25 FPS and 1080p resolution. One of: 6, 8, 10, 12, 14, 16, 18, 20. |
resolution | string | "1080p" | The resolution of the generated video. One of: 1080p, 1440p, 2160p. |
aspect_ratio | string | "auto" | The aspect ratio of the generated video. If ‘auto’, the aspect ratio will be determined automatically based on the input image. One of: auto, 16:9, 9:16. |
fps | integer | 25 | The frames per second of the generated video. One of: 24, 25, 48, 50. |
generate_audio | boolean | true | Whether to generate audio for the generated video. |