> ## Documentation Index
> Fetch the complete documentation index at: https://dripart-feat-openapi-i18n.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# RunwayFirstLastFrameNode - ComfyUI Built-in Node Documentation

> Complete documentation for the RunwayFirstLastFrameNode node in ComfyUI. Learn its inputs, outputs, parameters and usage.

The Runway First-Last-Frame to Video node generates videos by uploading first and last keyframes along with a text prompt. It creates smooth transitions between the provided start and end frames using Runway's Gen-3 model. This is particularly useful for complex transitions where the end frame differs significantly from the start frame.

## Inputs

| Parameter     | Description                                                          | Data Type | Required | Range                          |
| ------------- | -------------------------------------------------------------------- | --------- | -------- | ------------------------------ |
| `prompt`      | Text prompt for the generation (default: empty string)               | STRING    | Yes      | N/A                            |
| `start_frame` | Start frame to be used for the video                                 | IMAGE     | Yes      | N/A                            |
| `end_frame`   | End frame to be used for the video. Supported for gen3a\_turbo only. | IMAGE     | Yes      | N/A                            |
| `duration`    | Video duration in seconds (default: "5")                             | COMBO     | Yes      | `"5"`<br />`"10"`              |
| `ratio`       | Aspect ratio for the generated video (default: "768:1280")           | COMBO     | Yes      | `"768:1280"`<br />`"1280:768"` |
| `seed`        | Random seed for generation. Set to 0 for random seed (default: 0).   | INT       | No       | 0 to 4294967295                |

**Parameter Constraints:**

* The `prompt` must contain at least 1 character
* Both `start_frame` and `end_frame` must have maximum dimensions of 7999x7999 pixels
* Both `start_frame` and `end_frame` must have aspect ratios between 0.5 and 2.0
* The `end_frame` parameter is only supported when using the gen3a\_turbo model

## Outputs

| Output Name | Description                                                        | Data Type |
| ----------- | ------------------------------------------------------------------ | --------- |
| `output`    | The generated video transitioning between the start and end frames | VIDEO     |

> This documentation was AI-generated. If you find any errors or have suggestions for improvement, please feel free to contribute! [Edit on GitHub](https://github.com/Comfy-Org/embedded-docs/blob/main/comfyui_embedded_docs/docs/RunwayFirstLastFrameNode/en.md)

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