> ## Documentation Index
> Fetch the complete documentation index at: https://docs.screenframed.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Output Formats

Control output dimensions, DPR, file format, quality, transparency, and CDN usage.

Output controls define the file ScreenFramed stores and serves. They do not change how the source page is loaded unless you also change viewport or device settings.

## Format

```json
{
  "url": "https://example.com",
  "output": {
    "format": "webp"
  }
}
```

| Format | Use for |
|---|---|
| `png` | Lossless output, transparency, docs, design assets. |
| `webp` | Web delivery with smaller files. |
| `jpg` | Photos or non-transparent images where alpha is not needed. |

## Size

Set exact dimensions for OG images, directory cards, app store assets, and social formats:

```json
{
  "url": "https://example.com",
  "output": {
    "width": 1200,
    "height": 630,
    "format": "webp"
  }
}
```

If `output.width` and `output.height` are omitted, ScreenFramed derives dimensions from `aspect_ratio` or the capture viewport. The maximum output width or height is `6144`.

## DPR

`output.dpr` scales the final composed image. `capture_dpr` controls how the browser captures the page. Use them separately:

```json
{
  "url": "https://example.com",
  "capture_dpr": 2,
  "output": {
    "dpr": 2
  }
}
```

## Transparency

Transparent output requires `png` or `webp`:

```json
{
  "url": "https://example.com",
  "selector": ".card",
  "background_style": "transparent",
  "output": {
    "format": "png"
  }
}
```

JPG cannot preserve alpha and is rejected when `background_style` is `transparent`.

## CDN URLs

Successful captures return a CDN URL:

```json
{
  "url": "https://cdn.screenframed.com/r/cap_01KNS1WNPW9FCHZSK4XNTHMB0H.png"
}
```

Use the returned URL directly in docs, CMS entries, social templates, or product records. If you need local files, use the [CLI](/cli/capture) and `--output`.

The canonical render is stored once. Format and delivery behavior can use CDN transforms where appropriate.