react-query/docs/reference/onlineManager.md

---
id: OnlineManager
title: OnlineManager
---

The `OnlineManager` manages the online state within TanStack Query. It can be used to change the default event listeners or to manually change the online state.

> Per default, the `onlineManager` assumes an active network connection, and listens to the `online` and `offline` events on the `window` object to detect changes.

> In previous versions, `navigator.onLine` was used to determine the network status. However, it doesn't work well in Chromium based browsers. There are [a lot of issues](https://bugs.chromium.org/p/chromium/issues/list?q=navigator.online) around false negatives, which lead to Queries being wrongfully marked as `offline`.

> To circumvent this, we now always start with `online: true` and only listen to `online` and `offline` events to update the status.

> This should reduce the likelihood of false negatives, however, it might mean false positives for offline apps that load via serviceWorkers, which can work even without an internet connection.

Its available methods are:

- [`setEventListener`](#onlinemanagerseteventlistener)
- [`subscribe`](#onlinemanagersubscribe)
- [`setOnline`](#onlinemanagersetonline)
- [`isOnline`](#onlinemanagerisonline)

## `onlineManager.setEventListener`

`setEventListener` can be used to set a custom event listener:

```tsx
import NetInfo from '@react-native-community/netinfo'
import { onlineManager } from '@tanstack/react-query'

onlineManager.setEventListener((setOnline) => {
  return NetInfo.addEventListener((state) => {
    setOnline(!!state.isConnected)
  })
})
```

## `onlineManager.subscribe`

`subscribe` can be used to subscribe to changes in the online state. It returns an unsubscribe function:

```tsx
import { onlineManager } from '@tanstack/react-query'

const unsubscribe = onlineManager.subscribe((isOnline) => {
  console.log('isOnline', isOnline)
})
```

## `onlineManager.setOnline`

`setOnline` can be used to manually set the online state.

```tsx
import { onlineManager } from '@tanstack/react-query'

// Set to online
onlineManager.setOnline(true)

// Set to offline
onlineManager.setOnline(false)
```

**Options**

- `online: boolean`

## `onlineManager.isOnline`

`isOnline` can be used to get the current online state.

```tsx
const isOnline = onlineManager.isOnline()
```