---
title: 'Updating Applications'
description: "There are several ways to update an Electron application. The easiest and officially supported one is taking advantage of the built-in Squirrel framework and Electron's autoUpdater module."
slug: updates
hide_title: false
---

There are several ways to provide automatic updates to your Electron application.
The easiest and officially supported one is taking advantage of the built-in
[Squirrel](https://github.com/Squirrel) framework and
Electron's [autoUpdater](../api/auto-updater.md) module.

## Using cloud object storage (serverless)

For a simple serverless update flow, Electron's autoUpdater module can
check if updates are available by pointing to a static storage URL
containing latest release metadata.

When a new release is available, this metadata needs to be published to
cloud storage alongside the release itself. The metadata format is
different for macOS and Windows.

### Publishing release metadata

With Electron Forge, you can set up static file storage updates by publishing
metadata artifacts from the ZIP Maker (macOS) with `macUpdateManifestBaseUrl`
and the Squirrel.Windows Maker (Windows) with `remoteReleases`.

See Forge's [Auto updating from S3](https://www.electronforge.io/config/publishers/s3#auto-updating-from-s3)
guide for an end-to-end example.

<details>
<summary>Manual publishing</summary>

On macOS, Squirrel.Mac can receive updates by reading a `releases.json` file with the
following JSON format:

```json title='releases.json'
{
  "currentRelease": "1.2.3",
  "releases": [
    {
      "version": "1.2.1",
      "updateTo": {
        "version": "1.2.1",
        "pub_date": "2023-09-18T12:29:53+01:00",
        "notes": "These are some release notes innit",
        "name": "1.2.1",
        "url": "https://mycompany.example.com/myapp/releases/myrelease"
      }
    },
    {
      "version": "1.2.3",
      "updateTo": {
        "version": "1.2.3",
        "pub_date": "2024-09-18T12:29:53+01:00",
        "notes": "These are some more release notes innit",
        "name": "1.2.3",
        "url": "https://mycompany.example.com/myapp/releases/myrelease3"
      }
    }
  ]
}
```

On Windows, Squirrel.Windows can receive updates by reading from the RELEASES
file generated during the build process. This file details the `.nupkg` delta
package to update to.

```plaintext title='RELEASES'
B0892F3C7AC91D72A6271FF36905FEF8FE993520 electron-fiddle-0.36.3-full.nupkg 103298365
```

These files should live in the same directory as your release, under a folder
structure that is aware of your app's platform and architecture.

For example:

```plaintext
my-app-updates/
├─ darwin/
│  ├─ x64/
│  │  ├─ my-app-1.0.0-darwin-x64.zip
│  │  ├─ my-app-1.1.0-darwin-x64.zip
│  │  ├─ RELEASES.json
│  ├─ arm64/
│  │  ├─ my-app-1.0.0-darwin-arm64.zip
│  │  ├─ my-app-1.1.0-darwin-arm64.zip
│  │  ├─ RELEASES.json
├─ win32/
│  ├─ x64/
│  │  ├─ my-app-1.0.0-win32-x64.exe
│  │  ├─ my-app-1.0.0-win32-x64.nupkg
│  │  ├─ my-app-1.1.0-win32-x64.exe
│  │  ├─ my-app-1.1.0-win32-x64.nupkg
│  │  ├─ RELEASES
```

</details>

### Reading release metadata

The easiest way to consume metadata is by installing [update-electron-app][],
a drop-in Node.js module that sets up autoUpdater and prompts the user with
a native dialog.

For static storage updates, point the `updateSource.baseUrl` parameter to
the directory containing your release metadata files.

```js title="main.js" @ts-nocheck
const { updateElectronApp, UpdateSourceType } = require('update-electron-app')

updateElectronApp({
  updateSource: {
    type: UpdateSourceType.StaticStorage,
    baseUrl: `https://my-bucket.s3.amazonaws.com/my-app-updates/${process.platform}/${process.arch}`
  }
})
```

## Using update.electronjs.org

The Electron team maintains [update.electronjs.org][], a free and open-source
webservice that Electron apps can use to self-update. The service is designed
for Electron apps that meet the following criteria:

- App runs on macOS or Windows
- App has a public GitHub repository
- Builds are published to [GitHub Releases][gh-releases]
- Builds are [code-signed](./code-signing.md) **(macOS only)**

The easiest way to use this service is by installing [update-electron-app][],
a Node.js module preconfigured for use with update.electronjs.org.

Install the module using your Node.js package manager of choice:

```sh npm2yarn
npm install update-electron-app
```

Then, invoke the updater from your app's main process file:

```js title="main.js" @ts-nocheck
require('update-electron-app')()
```

By default, this module will check for updates at app startup, then every ten
minutes. When an update is found, it will automatically be downloaded in the background.
When the download completes, a dialog is displayed allowing the user to restart the app.

If you need to customize your configuration, you can
[pass options to update-electron-app][update-electron-app]
or
[use the update service directly][update.electronjs.org].

## Using other update services

If you're developing a private Electron application, or if you're not
publishing releases to GitHub Releases, it may be necessary to run your own
update server.

### Step 1: Deploying an update server

Depending on your needs, you can choose from one of these:

- [Hazel][hazel] – Update server for private or open-source apps which can be
  deployed for free on [Vercel][vercel]. It pulls from [GitHub Releases][gh-releases]
  and leverages the power of GitHub's CDN.
- [Nuts][nuts] – Also uses [GitHub Releases][gh-releases], but caches app
  updates on disk and supports private repositories.
- [electron-release-server][electron-release-server] – Provides a dashboard for
  handling releases and does not require releases to originate on GitHub.
- [Nucleus][nucleus] – A complete update server for Electron apps maintained by
  Atlassian. Supports multiple applications and channels; uses a static file store
  to minify server cost.

Once you've deployed your update server, you can instrument your app code to receive and
apply the updates with Electron's [autoUpdater](../api/auto-updater.md) module.

### Step 2: Receiving updates in your app

First, import the required modules in your main process code. The following code might
vary for different server software, but it works like described when using [Hazel][hazel].

:::warning Check your execution environment!

Please ensure that the code below will only be executed in your packaged app, and not in development.
You can use the [app.isPackaged](../api/app.md#appispackaged-readonly) API to check the environment.

:::

```js title='main.js'
const { app, autoUpdater, dialog } = require('electron')
```

Next, construct the URL of the update server feed and tell
[autoUpdater](../api/auto-updater.md) about it:

```js title='main.js'
const server = 'https://your-deployment-url.com'
const url = `${server}/update/${process.platform}/${app.getVersion()}`

autoUpdater.setFeedURL({ url })
```

As the final step, check for updates. The example below will check every minute:

```js title='main.js'
setInterval(() => {
  autoUpdater.checkForUpdates()
}, 60000)
```

Once your application is [packaged](./application-distribution.md),
it will receive an update for each new [GitHub Release][gh-releases] that you
publish.

### Step 3: Notifying users when updates are available

Now that you've configured the basic update mechanism for your application, you
need to ensure that the user will get notified when there's an update. This
can be achieved using the [autoUpdater API events](../api/auto-updater.md#events):

```js title="main.js" @ts-expect-error=[11]
autoUpdater.on('update-downloaded', (event, releaseNotes, releaseName) => {
  const dialogOpts = {
    type: 'info',
    buttons: ['Restart', 'Later'],
    title: 'Application Update',
    message: process.platform === 'win32' ? releaseNotes : releaseName,
    detail:
      'A new version has been downloaded. Restart the application to apply the updates.'
  }

  dialog.showMessageBox(dialogOpts).then((returnValue) => {
    if (returnValue.response === 0) autoUpdater.quitAndInstall()
  })
})
```

Also make sure that errors are
[being handled](../api/auto-updater.md#event-error). Here's an example
for logging them to `stderr`:

```js title="main.js"
autoUpdater.on('error', (message) => {
  console.error('There was a problem updating the application')
  console.error(message)
})
```

:::info Handling updates manually

Because the requests made by autoUpdate aren't under your direct control, you may find situations
that are difficult to handle (such as if the update server is behind authentication). The `url`
field supports the `file://` protocol, which means that with some effort, you can sidestep the
server-communication aspect of the process by loading your update from a local directory.
[Here's an example of how this could work](https://github.com/electron/electron/issues/5020#issuecomment-477636990).

:::

## Update server specification

For advanced deployment needs, you can also roll out your own Squirrel-compatible update server.
For example, you may want to have percentage-based rollouts, distribute your app through separate
release channels, or put your update server behind an authentication check.

Squirrel.Windows and Squirrel.Mac clients require different response formats,
but you can use a single server for both platforms by sending requests to
different endpoints depending on the value of `process.platform`.

```js title='main.js'
const { app, autoUpdater } = require('electron')

const server = 'https://your-deployment-url.com'
// e.g. for Windows and app version 1.2.3
// https://your-deployment-url.com/update/win32/1.2.3
const url = `${server}/update/${process.platform}/${app.getVersion()}`

autoUpdater.setFeedURL({ url })
```

### Windows

A Squirrel.Windows client expects the update server to return the `RELEASES` artifact
of the latest available build at the `/RELEASES` subpath of your endpoint.

For example, if your feed URL is `https://your-deployment-url.com/update/win32/1.2.3`,
then the `https://your-deployment-url.com/update/win32/1.2.3/RELEASES` endpoint
should return the contents of the `RELEASES` artifact of the version you want to serve.

```plaintext title='https://your-deployment-url.com/update/win32/1.2.3/RELEASES'
B0892F3C7AC91D72A6271FF36905FEF8FE993520 https://your-static.storage/your-app-1.2.3-full.nupkg 103298365
```

Squirrel.Windows does the comparison check to see if the current app should update to
the version returned in `RELEASES`, so you should return a response even when no update
is available.

### macOS

When an update is available, the Squirrel.Mac client expects a JSON response at the feed URL's endpoint.
This object has a mandatory `url` property that maps to a ZIP archive of the
app update. All other properties in the object are optional.

```json title='https://your-deployment-url.com/update/darwin/0.31.0'
{
    "url": "https://your-static.storage/your-app-1.2.3-darwin.zip",
    "name": "1.2.3",
    "notes": "These are some release notes innit",
    "pub_date": "2024-09-18T12:29:53+01:00"
}
```

If no update is available, the server should return a [`204 No Content`](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/204)
HTTP response.

[vercel]: https://vercel.com
[hazel]: https://github.com/vercel/hazel
[nuts]: https://github.com/GitbookIO/nuts
[gh-releases]: https://docs.github.com/en/repositories/releasing-projects-on-github/managing-releases-in-a-repository#creating-a-release
[electron-release-server]: https://github.com/ArekSredzki/electron-release-server
[nucleus]: https://github.com/atlassian/nucleus
[update.electronjs.org]: https://github.com/electron/update.electronjs.org
[update-electron-app]: https://github.com/electron/update-electron-app
