---
hide_title: false
hide_table_of_contents: false
pagination_next: null
pagination_prev: null
---

# Device.lookup()

Look up the data associated with a particular User-Agent string.


## Syntax

```js
lookup(userAgent)
```

### Return value

If there is data associated with the User-Agent, a `Device` instance is returned.
Otherwise, `null` is returned.
