> For the complete documentation index, see [llms.txt](https://developer.topazlabs.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.topazlabs.com/video-models/upscaling-and-enhancement/generative/starlight-fast-2.md).

# Starlight Fast 2

2x faster diffusion upscaling with higher fidelity

<table data-card-size="large" data-view="cards"><thead><tr><th align="center"></th><th data-hidden data-card-cover data-type="image">Cover image</th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td align="center">Click to view</td><td><a href="https://4007072434-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FJkSwaYgAsTQke14gpXAF%2Fuploads%2FtJ6UpzLD7BqYlDHmG2Xi%2FStarlight_Fast_2_slider.jpg?alt=media&#x26;token=fb24656a-3977-46d4-a8bb-e2e95de7ed9e">https://4007072434-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FJkSwaYgAsTQke14gpXAF%2Fuploads%2FtJ6UpzLD7BqYlDHmG2Xi%2FStarlight_Fast_2_slider.jpg?alt=media&#x26;token=fb24656a-3977-46d4-a8bb-e2e95de7ed9e</a></td><td><a href="https://compare.topazlabs.com/share/video?src1=https%3A%2F%2Fdownloads.topazlabs.com%2Fweb-assets%2Fmodel-examples%2FWorldsFair0001-before.mp4&#x26;src1label=Before&#x26;src2=https%3A%2F%2Fdownloads.topazlabs.com%2Fweb-assets%2Fmodel-examples%2FWorldsFair0001-before_Precise_Starlight_Fast_2.mp4&#x26;src2label=After&#x26;zoom=1">https://compare.topazlabs.com/share/video?src1=https%3A%2F%2Fdownloads.topazlabs.com%2Fweb-assets%2Fmodel-examples%2FWorldsFair0001-before.mp4&#x26;src1label=Before&#x26;src2=https%3A%2F%2Fdownloads.topazlabs.com%2Fweb-assets%2Fmodel-examples%2FWorldsFair0001-before_Precise_Starlight_Fast_2.mp4&#x26;src2label=After&#x26;zoom=1</a></td></tr><tr><td align="center">Click to view</td><td><a href="https://4007072434-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FJkSwaYgAsTQke14gpXAF%2Fuploads%2FAIAo6hVxXq2t86eS3FrK%2FStarlight_Fast_2_-_6429487_Woodpecker_Bird_Autumn_Telephoto_By_Edwin_Haighton_Artlist_4K_slider.jpg?alt=media&#x26;token=1936fc48-a0ab-4330-a1e3-a9faa4deff61">https://4007072434-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FJkSwaYgAsTQke14gpXAF%2Fuploads%2FAIAo6hVxXq2t86eS3FrK%2FStarlight_Fast_2_-_6429487_Woodpecker_Bird_Autumn_Telephoto_By_Edwin_Haighton_Artlist_4K_slider.jpg?alt=media&#x26;token=1936fc48-a0ab-4330-a1e3-a9faa4deff61</a></td><td><a href="https://compare.topazlabs.com/share/video?src1=https%3A%2F%2Fdownloads.topazlabs.com%2Fweb-assets%2Fmodel-examples%2F6429487_Woodpecker%20Bird%20Autumn%20Telephoto_By_Edwin_Haighton_Artlist_4K.mp4&#x26;src1label=Before&#x26;src2=https%3A%2F%2Fdownloads.topazlabs.com%2Fweb-assets%2Fmodel-examples%2F6429487_Woodpecker%20Bird%20Autumn%20Telephoto_By_Edwin_Haighton_Artlist_4K_slf.mp4&#x26;src2label=Starlight%20Fast%202&#x26;zoom=1">https://compare.topazlabs.com/share/video?src1=https%3A%2F%2Fdownloads.topazlabs.com%2Fweb-assets%2Fmodel-examples%2F6429487_Woodpecker%20Bird%20Autumn%20Telephoto_By_Edwin_Haighton_Artlist_4K.mp4&#x26;src1label=Before&#x26;src2=https%3A%2F%2Fdownloads.topazlabs.com%2Fweb-assets%2Fmodel-examples%2F6429487_Woodpecker%20Bird%20Autumn%20Telephoto_By_Edwin_Haighton_Artlist_4K_slf.mp4&#x26;src2label=Starlight%20Fast%202&#x26;zoom=1</a></td></tr></tbody></table>

### Model Overview

Starlight Fast 2 is a second generation diffusion-based video enhancement model designed for improved speed and quality. It delivers significantly faster results than Fast 1 while producing more realistic outputs and sharper details.

Fast 2 balances performance and quality, making it suited for high volume processing, rapid turnaround workflows, and scenarios where speed is critical but visual fidelity still matters.

### Best Use Cases

* **Price-sensitive workloads.** The lowest-cost Starlight model.
* **High-volume batches.** Generative results at lower cost.
* **Previews.** Inexpensive test passes.
* **GenAI video.** Fast generative upscaling.
* **Existing pipelines.** Consistent results for projects already using Fast 2.

### Endpoint

`https://api.topazlabs.com/video/`

`https://api.topazlabs.com/video/express`

### Model Parameters

Model parameters go inside the filter object in `filters`.

| Parameter | Type     | Required / Default | Accepted values | Description |
| --------- | -------- | ------------------ | --------------- | ----------- |
| `model`   | `string` | Required           | `"slf-2"`       | —           |

Starlight Fast 2 has no model-specific parameters.

For request parameters shared by every video model (source, output, destination, and notifications), see Request Parameters. The full schema is also available in our API Reference page.

### Model Pricing

**Starlight Fast 2** is priced per output frame. Credits = ceil(output frames ÷ frames per credit).

| Output resolution | Frames per credit |
| ----------------- | ----------------- |
| 1080p             | 52.0833           |
| 4K                | 23.8357           |

#### 1080p Output

| Duration | 24 fps | 30 fps | 60 fps |
| -------- | ------ | ------ | ------ |
| 5 s      | 3      | 3      | 6      |
| 10 s     | 5      | 6      | 12     |
| 30 s     | 14     | 18     | 35     |
| 1 min    | 28     | 35     | 70     |
| 5 min    | 139    | 173    | 346    |
| 10 min   | 277    | 346    | 692    |

#### 4K Output

| Duration | 24 fps | 30 fps | 60 fps |
| -------- | ------ | ------ | ------ |
| 5 s      | 6      | 7      | 13     |
| 10 s     | 11     | 13     | 26     |
| 30 s     | 31     | 38     | 76     |
| 1 min    | 61     | 76     | 152    |
| 5 min    | 303    | 378    | 756    |
| 10 min   | 605    | 756    | 1511   |

{% hint style="info" %}
These are estimates. For a quote on a specific file, use our [Credit Calculator](https://developer.topazlabs.com/credit-calculator) or create the request with `POST /video/`, which returns an estimate before processing starts.
{% endhint %}

### Example Request

{% tabs %}
{% tab title="cURL" %}

```bash
curl -X POST "https://api.topazlabs.com/video/express" \
  -H "X-API-Key: $TOPAZ_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "source": { "container": "mp4" },
    "filters": [ { "model": "slf-2" } ],
    "output": { "resolution": { "width": 3840, "height": 2160 } }
  }'
```

{% endtab %}

{% tab title="JavaScript" %}

```javascript
const payload = {
  "source": {
    "container": "mp4"
  },
  "filters": [
    {
      "model": "slf-2"
    }
  ],
  "output": {
    "resolution": {
      "width": 3840,
      "height": 2160
    }
  }
};

const response = await fetch("https://api.topazlabs.com/video/express", {
  method: 'POST',
  headers: {
    'X-API-Key': process.env.TOPAZ_API_KEY,
    'Content-Type': 'application/json',
  },
  body: JSON.stringify(payload),
});

if (!response.ok) {
  throw new Error(`Request failed: ${response.status} ${await response.text()}`);
}

console.log(await response.json());
```

{% endtab %}

{% tab title="Python" %}

```python
import os
import requests

payload = {'source': {'container': 'mp4'},
 'filters': [{'model': 'slf-2'}],
 'output': {'resolution': {'width': 3840, 'height': 2160}}}

response = requests.post(
    "https://api.topazlabs.com/video/express",
    headers={"X-API-Key": os.environ["TOPAZ_API_KEY"]},
    json=payload,
)
response.raise_for_status()
print(response.json())
```

{% endtab %}
{% endtabs %}

### Helpful Resources

<table data-view="cards"><thead><tr><th></th><th></th><th></th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td><i class="fa-play">:play:</i></td><td><h4>Video Quickstart</h4></td><td>Quickly get started with our Video API.</td><td><a href="/getting-started/video-quickstart.md">Video Quickstart</a></td></tr><tr><td><i class="fa-file-brackets-curly">:file-brackets-curly:</i></td><td><h4>API Reference</h4></td><td>View our API reference to view the entire schema.</td><td><a href="https://developer.topazlabs.com/reference/">Reference</a></td></tr><tr><td><i class="fa-square-root-variable">:square-root-variable:</i></td><td><h4>Model Pricing</h4></td><td>Learn how we price our models.</td><td><a href="/getting-started/model-pricing.md">Model Pricing</a></td></tr></tbody></table>


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