---
title: USBDevice.open()
slug: Web/API/USBDevice/open
tags:
  - API
  - Method
  - Reference
  - USB
  - USBDevice
  - WebUSB
  - WebUSB API
  - open
browser-compat: api.USBDevice.open
---
{{APIRef("WebUSB API")}}{{SeeCompatTable}}

The **`open()`** method of the {{domxref("USBDevice")}}
interface returns a {{jsxref("promise")}} that resolves when a device session has
started.

## Syntax

```js
var promise = USBDevice.open()
```

### Parameters

None.

### Return value

A {{jsxref("promise")}}.

## Specifications

{{Specifications}}

## Browser compatibility

{{Compat}}
