﻿---
title: JavaScript
description: This is the official Node.js client for Elasticsearch. This page gives a quick overview about the features of the client. One-to-one mapping with REST...
url: https://www.elastic.co/elastic/docs-builder/docs/2847/reference/elasticsearch/clients/javascript
products:
  - Elasticsearch
  - Elasticsearch Client
  - Elasticsearch JavaScript Client
---

# JavaScript
This is the official Node.js client for Elasticsearch. This page gives a quick overview about the features of the client.

## Features

- One-to-one mapping with REST API.
- Generalized, pluggable architecture.
- Configurable, automatic discovery of cluster nodes.
- Persistent, Keep-Alive connections.
- Load balancing across all available nodes.
- Child client support.
- TypeScript support out of the box.


### Install multiple versions

If you are using multiple versions of Elasticsearch, you need to use multiple versions of the client as well. In the past, installing multiple versions of the same package was not possible, but with `npm v6.9`, you can do it via aliasing.
To install different version of the client, run the following command:
```sh
npm install <alias>@npm:@elastic/elasticsearch@<version>
```

For example, if you need to install `7.x` and `6.x`, run the following commands:
```sh
npm install es6@npm:@elastic/elasticsearch@6
npm install es7@npm:@elastic/elasticsearch@7
```

Your `package.json` will look similar to the following example:
```json
"dependencies": {
  "es6": "npm:@elastic/elasticsearch@^6.7.0",
  "es7": "npm:@elastic/elasticsearch@^7.0.0"
}
```

Require the packages from your code by using the alias you have defined.
```js
const { Client: Client6 } = require('es6')
const { Client: Client7 } = require('es7')

const client6 = new Client6({
  cloud: { id: '<cloud-id>' },
  auth: { apiKey: 'base64EncodedKey' }
})
const client7 = new Client7({
  cloud: { id: '<cloud-id>' },
  auth: { apiKey: 'base64EncodedKey' }
})

client6.info().then(console.log, console.log)
client7.info().then(console.log, console.log)
```

Finally, if you want to install the client for the next version of Elasticsearch (the one that lives in the Elasticsearch main branch), use the following command:
```sh
npm install esmain@github:elastic/elasticsearch-js
```

<warning>
  This command installs the main branch of the client which is not considered stable.
</warning>