---
title: Test Responsive and Mobile Layouts
description: Emulate viewports, devices, touch, locale, timezone, and geolocation to test how your app renders across screen sizes.
---

# Test Responsive and Mobile Layouts

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Test how your app looks on different screen sizes and devices.

```
/shiplight verify http://localhost:3000 on mobile (390x844 viewport, touch enabled) —
check that the hamburger menu appears instead of the desktop navigation bar.
```

Available emulation options:

| Option         | Example               | Description                             |
| -------------- | --------------------- | --------------------------------------- |
| `viewport`     | `390x844`, `768x1024` | Screen dimensions                       |
| `is_mobile`    | —                     | Mobile CSS media queries, meta viewport |
| `has_touch`    | —                     | Touch events                            |
| `user_agent`   | Custom UA string      | Override the browser user agent         |
| `color_scheme` | `dark`, `light`       | Emulated color scheme                   |
| `locale`       | `ja-JP`, `fr-FR`      | Browser locale                          |
| `timezone_id`  | `America/New_York`    | Emulated timezone                       |
| `geolocation`  | lat/lng coordinates   | Emulated GPS location                   |

For the full `browser_options` reference, see [Browser Options](/reference/browser-options).