is-online

Check if the internet connection is up

Offline
sindresorhus/is-onlineis-online

README

is-online


Check if the internet connection is up


Works in Node.js and the browser (with a bundler).

In the browser, there is already [navigator.onLine](https://developer.mozilla.org/en-US/docs/Web/API/NavigatorOnLine.onLine), but it's useless as it only tells you if there's a local connection, and not whether the internet is accessible.

Install


  1. ```sh
  2. npm install is-online
  3. ```

Usage


  1. ```js
  2. import isOnline from 'is-online';

  4. console.log(await isOnline());
  5. //=> true
  6. ```

API


isOnline(options?)


options


Type: object

timeout

Type: number\
Default: 5000

Milliseconds to wait for a server to respond.

ipVersion

Type: number\
Values: 4 | 6\
Default: 4

The Internet Protocol version to use.

This is an advanced option that is usually not necessary to be set, but it can prove useful to specifically assert IPv6 connectivity.

How it works


The following checks are run in parallel:

- Retrieve icanhazip.com (or ipify.org as fallback) via HTTPS.
- Query myip.opendns.com and o-o.myaddr.l.google.com DNS entries. (Node.js only)
- Retrieve Apple's Captive Portal test page (this is what iOS does). (Node.js only)

When any check succeeds, the returned Promise is resolved to true.

Proxy support


To make it work through proxies, you need to set up [global-agent](https://github.com/gajus/global-agent).

Maintainers


- Sindre Sorhus
- silverwind

Related


- is-online-cli - CLI for this module
- is-reachable - Check if servers are reachable