# SDXL Lightning 4-step

> ByteDance's 4-step SDXL Lightning — the most-run model on Replicate (1B+ runs). Near-instant 1024px image generation at very low cost.

- **Provider**: replicate
- **Model ID**: bytedance/sdxl-lightning-4step
- **Category**: image_generation
- **Credits**: 4 per request
- **Pricing Type**: input_based

## API Endpoint

Base URL: https://api.core.today/v1

### Create Prediction
POST /predictions

### Get Status
GET /predictions/{job_id}

### Cancel
DELETE /predictions/{job_id}

## Authentication

Header: `X-API-Key: YOUR_API_KEY`

## Input Parameters

- `num_outputs` (integer, optional): Number of images to output. (Default: `1`; Range: min: 1, max: 4)
- `height` (integer, optional): Height of output image. Recommended 1024 or 1280 (Default: `1024`; Range: min: 256, max: 1280)
- `disable_safety_checker` (boolean, optional): Disable safety checker for generated images (Default: `False`)
- `prompt` (string, optional): Input prompt (Default: `self-portrait of a woman, lightning in the background`)
- `guidance_scale` (number, optional): Scale for classifier-free guidance (Default: `0`; Range: min: 0, max: 50)
- `num_inference_steps` (integer, optional): Number of denoising steps. 4 for best results (Default: `4`; Range: min: 1, max: 10)
- `scheduler` (string, optional): scheduler (Default: `K_EULER`; Options: `DDIM`, `DPMSolverMultistep`, `HeunDiscrete`, `KarrasDPM`, `K_EULER_ANCESTRAL`, `K_EULER`, `PNDM`, `DPM++2MSDE`)
- `width` (integer, optional): Width of output image. Recommended 1024 or 1280 (Default: `1024`; Range: min: 256, max: 1280)
- `negative_prompt` (string, optional): Negative Input prompt (Default: `worst quality, low quality`)
- `seed` (integer, optional): Random seed. Leave blank to randomize the seed (Default: `0`)

## Example Request

```json
{
  "model": "bytedance/sdxl-lightning-4step",
  "input": {
    "scheduler": "K_EULER",
    "num_outputs": 1,
    "negative_prompt": "worst quality, low quality",
    "guidance_scale": 0,
    "width": 1024,
    "prompt": "self-portrait of a woman, lightning in the background",
    "height": 1024,
    "num_inference_steps": 4
  }
}
```

## Response Format

```json
{
  "job_id": "abc123",
  "status": "pending",
  "provider": "replicate",
  "model": "black-forest-labs/flux-schnell",
  "created_at": "2026-01-01T00:00:00Z",
  "result": null,
  "error": null
}
```

Status values: `pending`, `processing`, `completed`, `failed`, `cancelled`

## Usage Flow

1. POST /predictions with model and input → receive job_id
2. Poll GET /predictions/{job_id} until status is `completed` or `failed`
3. Result contains output URL(s) or data

## Output Type

url

## Tags

text-to-image, sdxl, lightning, fast, bytedance, low-cost

## Documentation

https://replicate.com/bytedance/sdxl-lightning-4step