# assertScreenshot

The `assertScreenshot` command takes a screenshot and matches it against a known good image, performing a visual regression test.

The assertion will fail if the comparison image is too dissimilar, or doesn't exist.

### Syntax

```yaml
- assertScreenshot: splash.png
```

or

```yaml
- assertScreenshot:
    path: screen.png
    cropOn:
      id: banner
    thresholdPercentage: 98
```

### Parameters

| Parameter             | Type             | Description                                                                                                                                                                                                                                                     |
| --------------------- | ---------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `path`                | String           | Path to the reference screenshot that the current screen will be compared against. Can be a JavaScript expression. Was likely created by a [takeScreenshot](https://docs.maestro.dev/reference/commands-available/takescreenshot) invocation in a previous run. |
| `cropOn`              | Element Selector | Optional. A selector to narrow the screenshot before comparison. The comparison screenshot must also have been cropped. For a complete list of all available selectors, see the [Selectors](https://docs.maestro.dev/api-reference/selectors) documentation.    |
| `thresholdPercentage` | Double           | Optional. Percentage match required to pass this assertion. Default is `95.0.`                                                                                                                                                                                  |
| `label`               | String           | Optional. A message to display when executing the evaluation.                                                                                                                                                                                                   |

### Usage Examples