@kesha-antonov/react-native-background-downloader

A library for React-Native to help you download large files on iOS and Android both in the foreground and most importantly in the background.

Why?

On iOS, if you want to download big files no matter the state of your app, wether it's in the background or terminated by the OS, you have to use a system API called NSURLSession.

This API handles your downloads separately from your app and only keeps it informed using delegates (Read: Downloading Files in the Background).

On Android we are using similar process with DownloadManager

The real challenge of using this method is making sure the app's UI is always up-to-date with the downloads that are happening in another process because your app might startup from scratch while the downloads are still running.

@kesha-antonov/react-native-background-downloader gives you an easy API to both downloading large files and re-attaching to those downloads once your app launches again.

Getting started

yarn add @kesha-antonov/react-native-background-downloader

or

npm i @kesha-antonov/react-native-background-downloader

Then:

cd ios && pod install

New Architecture Support

This library supports React Native's New Architecture (Fabric + TurboModules) starting from React Native 0.70+.

Automatic Detection

The library automatically detects whether the New Architecture is enabled in your app and uses the appropriate implementation:

New Architecture: Uses TurboModules for optimal performance
Legacy Architecture: Uses the traditional bridge implementation

Manual Setup (Advanced)

If you need to manually configure the package for New Architecture:

iOS: The library automatically detects New Architecture via compile-time flags.

Android: For New Architecture, you can optionally use RNBackgroundDownloaderTurboPackage instead of the default package:

import com.eko.RNBackgroundDownloaderTurboPackage;

// In your MainApplication.java
@Override
protected List<ReactPackage> getPackages() {
  return Arrays.<ReactPackage>asList(
    // ... other packages
    new RNBackgroundDownloaderTurboPackage() // For New Architecture
  );
}

Known Issues with New Architecture

When using larger files with the New Architecture, you may encounter ERROR_CANNOT_RESUME (error code 1008). This is a known limitation of Android's DownloadManager, not specific to this library or the New Architecture. The error includes enhanced messaging to help diagnose the issue.

Workaround: If you encounter this error frequently with large files, consider:

Breaking large downloads into smaller chunks
Implementing retry logic in your app
Using alternative download strategies for very large files

The library now provides enhanced error handling for this specific case with detailed logging and cleanup.

Mostly automatic installation

Any React Native version >= 0.60 supports autolinking so nothing should be done.

For anything < 0.60 run the following link command

$ react-native link @kesha-antonov/react-native-background-downloader

Manual installation

iOS

In XCode, in the project navigator, right click Libraries ➜ Add Files to [your project's name]
Go to node_modules ➜ @kesha-antonov/react-native-background-downloader and add RNBackgroundDownloader.xcodeproj
In XCode, in the project navigator, select your project. Add libRNBackgroundDownloader.a to your project's Build Phases ➜ Link Binary With Libraries
Run your project (Cmd+R)

Android

Open up android/app/src/main/java/[...]/MainActivity.java

Add import com.eko.RNBackgroundDownloaderPackage; to the imports at the top of the file
Add new RNBackgroundDownloaderPackage() to the list returned by the getPackages() method

Append the following lines to android/settings.gradle:

include ':react-native-background-downloader'
project(':react-native-background-downloader').projectDir = new File(rootProject.projectDir,   '../node_modules/@kesha-antonov/react-native-background-downloader/android')

Insert the following lines inside the dependencies block in android/app/build.gradle:
```
  compile project(':react-native-background-downloader')
```

iOS - Extra Mandatory Step

Option 1: Using Expo Config Plugin (Recommended for Expo/EAS users)

If you're using Expo or EAS Build, you can use the included Expo config plugin to automatically configure the iOS native code:

In your app.json:

{
  "expo": {
    "name": "Your App",
    "plugins": [
      "@kesha-antonov/react-native-background-downloader"
    ]
  }
}

Or in your app.config.js:

export default {
  expo: {
    name: "Your App",
    plugins: [
      "@kesha-antonov/react-native-background-downloader"
    ]
  }
}

The plugin will automatically:

Add the required import to your AppDelegate (Objective-C) or Bridging Header (Swift)
Add the handleEventsForBackgroundURLSession method to your AppDelegate
Handle both React Native < 0.77 (Objective-C) and >= 0.77 (Swift) projects

After adding the plugin, run:

expo prebuild --clean

Option 2: Manual Setup

Manual setup for React Native 0.77+ (Click to expand)

In your project bridging header file (e.g. ios/{projectName}-Bridging-Header.h) add an import for RNBackgroundDownloader:

...
#import <RNBackgroundDownloader.h>

Then in your AppDelegate.swift add the following method inside of your AppDelegate class:

...

@main
class AppDelegate: UIResponder, UIApplicationDelegate
  ...

  func application(
    _ application: UIApplication,
    handleEventsForBackgroundURLSession identifier: String,
    completionHandler: @escaping () -> Void
  ) {
    RNBackgroundDownloader.setCompletionHandlerWithIdentifier(identifier, completionHandler: completionHandler)
  }
}
...

Failing to add this code will result in canceled background downloads. If Xcode complains that RNBackgroundDownloader.h is missing, you might have forgotten to pod install first.

Manual setup for React Native < 0.77 (Click to expand)

In your AppDelegate.m add the following code:

...
#import <RNBackgroundDownloader.h>

...

- (void)application:(UIApplication *)application handleEventsForBackgroundURLSession:(NSString *)identifier completionHandler:(void (^)(void))completionHandler
{
  [RNBackgroundDownloader setCompletionHandlerWithIdentifier:identifier completionHandler:completionHandler];
}

...

Failing to add this code will result in canceled background downloads. If Xcode complains that RNBackgroundDownloader.h is missing, you might have forgotten to pod install first.

Usage

Downloading a file

import { Platform } from 'react-native'
import { download, completeHandler, directories } from '@kesha-antonov/react-native-background-downloader'

const jobId = 'file123'

let task = download({
  id: jobId,
  url: 'https://link-to-very.large/file.zip',
  destination: `${directories.documents}/file.zip`,
  metadata: {}
}).begin(({ expectedBytes, headers }) => {
  console.log(`Going to download ${expectedBytes} bytes!`)
}).progress(({ bytesDownloaded, bytesTotal }) => {
  console.log(`Downloaded: ${bytesDownloaded / bytesTotal * 100}%`)
}).done(({ bytesDownloaded, bytesTotal }) => {
  console.log('Download is done!', { bytesDownloaded, bytesTotal })

  // PROCESS YOUR STUFF

  // FINISH DOWNLOAD JOB
  completeHandler(jobId)
}).error(({ error, errorCode }) => {
  console.log('Download canceled due to error: ', { error, errorCode });
})

// Pause the task (iOS only)
// Note: On Android, pause/resume is not supported by DownloadManager
task.pause()

// Resume after pause (iOS only)
// Note: On Android, pause/resume is not supported by DownloadManager
task.resume()

// Cancel the task
task.stop()

Platform-Aware Pause/Resume

import { Platform } from 'react-native'
import { download, directories } from '@kesha-antonov/react-native-background-downloader'

let task = download({
  id: 'file123',
  url: 'https://link-to-very.large/file.zip',
  destination: `${directories.documents}/file.zip`,
  metadata: {}
}).begin(({ expectedBytes, headers }) => {
  console.log(`Going to download ${expectedBytes} bytes!`)
}).progress(({ bytesDownloaded, bytesTotal }) => {
  console.log(`Downloaded: ${bytesDownloaded / bytesTotal * 100}%`)
}).done(({ bytesDownloaded, bytesTotal }) => {
  console.log('Download is done!', { bytesDownloaded, bytesTotal })
}).error(({ error, errorCode }) => {
  console.log('Download canceled due to error: ', { error, errorCode });
})

// Platform-aware pause/resume handling
function pauseDownload() {
  if (Platform.OS === 'ios') {
    task.pause()
    console.log('Download paused')
  } else {
    console.log('Pause not supported on Android. Consider using stop() instead.')
  }
}

function resumeDownload() {
  if (Platform.OS === 'ios') {
    task.resume()
    console.log('Download resumed')
  } else {
    console.log('Resume not supported on Android. You may need to restart the download.')
  }
}

Re-Attaching to background downloads

This is the main selling point of this library (but it's free!).

What happens to your downloads after the OS stopped your app? Well, they are still running, we just need to re-attach to them.

Add this code to app's init stage, and you'll never lose a download again!

import RNBackgroundDownloader from '@kesha-antonov/react-native-background-downloader'

let lostTasks = await RNBackgroundDownloader.checkForExistingDownloads()
for (let task of lostTasks) {
  console.log(`Task ${task.id} was found!`)
  task.progress(({ bytesDownloaded, bytesTotal }) => {
    console.log(`Downloaded: ${bytesDownloaded / bytesTotal * 100}%`)
  }).done(({ bytesDownloaded, bytesTotal }) => {
    console.log('Download is done!', { bytesDownloaded, bytesTotal })
  }).error(({ error, errorCode }) => {
    console.log('Download canceled due to error: ', { error, errorCode })
  })
}

task.id is very important for re-attaching the download task with any UI component representing that task. This is why you need to make sure to give sensible IDs that you know what to do with, try to avoid using random IDs.

Using custom headers

If you need to send custom headers with your download request, you can do in it 2 ways:

Globally using RNBackgroundDownloader.setConfig():

RNBackgroundDownloader.setConfig({
  headers: {
    Authorization: 'Bearer 2we$@$@Ddd223',
  }
})

This way, all downloads with have the given headers.

Per download by passing a headers object in the options of RNBackgroundDownloader.download():

let task = RNBackgroundDownloader.download({
  id: 'file123',
  url: 'https://link-to-very.large/file.zip'
  destination: `${RNBackgroundDownloader.directories.documents}/file.zip`,
  headers: {
    Authorization: 'Bearer 2we$@$@Ddd223'
  }
}).begin(({ expectedBytes, headers }) => {
  console.log(`Going to download ${expectedBytes} bytes!`)
}).progress(({ bytesDownloaded, bytesTotal }) => {
  console.log(`Downloaded: ${bytesDownloaded / bytesTotal * 100}%`)
}).done(({ bytesDownloaded, bytesTotal }) => {
  console.log('Download is done!', { bytesDownloaded, bytesTotal })
}).error(({ error, errorCode }) => {
  console.log('Download canceled due to error: ', { error, errorCode })
})

Headers given in the download function are merged with the ones given in setConfig({ headers: { ... } }).

Handling Slow-Responding URLs

This library automatically includes connection timeout improvements for slow-responding URLs. By default, the following headers are added to all download requests on Android:

Connection: keep-alive - Keeps the connection open for better handling
Keep-Alive: timeout=600, max=1000 - Sets a 10-minute keep-alive timeout
User-Agent: ReactNative-BackgroundDownloader/3.2.6 - Proper user agent for better server compatibility

These headers help prevent downloads from getting stuck in "pending" state when servers take several minutes to respond initially. You can override these headers by providing your own in the headers option.

Handling URLs with Many Redirects (Android)

Android's DownloadManager has a built-in redirect limit that can cause ERROR_TOO_MANY_REDIRECTS for URLs with multiple redirects (common with podcast URLs, tracking services, CDNs, etc.).

To handle this, you can use the maxRedirects option to pre-resolve redirects before passing the final URL to DownloadManager:

import { Platform } from 'react-native'
import { download, directories } from '@kesha-antonov/react-native-background-downloader'

// Example: Podcast URL with multiple redirects
let task = download({
  id: 'podcast-episode',
  url: 'https://pdst.fm/e/chrt.fm/track/479722/arttrk.com/p/example.mp3',
  destination: `${directories.documents}/episode.mp3`,
  maxRedirects: 10, // Follow up to 10 redirects before downloading
}).begin(({ expectedBytes }) => {
  console.log(`Going to download ${expectedBytes} bytes!`)
}).progress(({ bytesDownloaded, bytesTotal }) => {
  console.log(`Downloaded: ${bytesDownloaded / bytesTotal * 100}%`)
}).done(({ bytesDownloaded, bytesTotal }) => {
  console.log('Download is done!', { bytesDownloaded, bytesTotal })
}).error(({ error, errorCode }) => {
  console.log('Download canceled due to error: ', { error, errorCode })

  if (errorCode === 1005) { // ERROR_TOO_MANY_REDIRECTS
    console.log('Consider increasing maxRedirects or using a different URL')
  }
})

Notes on maxRedirects:

Only available on Android (iOS handles redirects automatically)
If not specified or set to 0, no redirect resolution is performed
Uses HEAD requests to resolve redirects efficiently
Falls back to original URL if redirect resolution fails
Respects the same headers and timeouts as the main download

API

RNBackgroundDownloader

`download(options)`

Download a file to destination

options

An object containing options properties

Property	Type	Required	Platforms	Info
`id`	String	✅	All	A Unique ID to provide for this download. This ID will help to identify the download task when the app re-launches
`url`	String	✅	All	URL to file you want to download
`destination`	String	✅	All	Where to copy the file to once the download is done
`metadata`	Object		All	Data to be preserved on reboot.
`headers`	Object		All	Costume headers to add to the download request. These are merged with the headers given in the `setConfig({ headers: { ... } })` function
`maxRedirects`	Number		Android	Maximum number of redirects to follow before passing URL to DownloadManager. If not specified or 0, no redirect resolution is performed. Helps avoid ERROR_TOO_MANY_REDIRECTS for URLs with many redirects (e.g., podcast URLs)
`isAllowedOverRoaming`	Boolean		Android	whether this download may proceed over a roaming connection. By default, roaming is allowed
`isAllowedOverMetered`	Boolean		Android	Whether this download may proceed over a metered network connection. By default, metered networks are allowed
`isNotificationVisible`	Boolean		Android	Whether to show a download notification or not
`notificationTitle`	String		Android	Title of the download notification

returns

DownloadTask - The download task to control and monitor this download

`checkForExistingDownloads()`

Checks for downloads that ran in background while you app was terminated. And also forces them to resume downloads.

Recommended to run at the init stage of the app.

returns

DownloadTask[] - Array of tasks that were running in the background so you can re-attach callbacks to them

`setConfig({})`

Name	Type	Info
`headers`	Object	optional headers to use in all future downloads
`progressInterval`	Number	Interval in which download progress sent from downloader. Number should be >= 250. It's in ms
`progressMinBytes`	Number	Minimum number of bytes that must be downloaded before triggering progress callbacks. Used for hybrid progress reporting (triggers on either percentage >1% OR bytes threshold). Default is 1048576 (1MB). Number should be >= 0
`isLogsEnabled`	Boolean	Enables/disables logs in library

DownloadTask

A class representing a download task created by RNBackgroundDownloader.download

`Members`

Name	Type	Info
`id`	String	The id you gave the task when calling `RNBackgroundDownloader.download`
`metadata`	Object	The metadata you gave the task when calling `RNBackgroundDownloader.download`
`bytesDownloaded`	Number	The number of bytes currently written by the task
`bytesTotal`	Number	The number bytes expected to be written by this task or more plainly, the file size being downloaded

`completeHandler(jobId)`

Finishes download job and informs OS that app can be closed in background if needed. After finishing download in background you have some time to process your JS logic and finish the job.

`ensureDownloadsAreRunning` (iOS only)

Pauses and resumes all downloads - this is fix for stuck downloads. Use it when your app loaded and is ready for handling downloads (all your logic loaded and ready to handle download callbacks).

Here's example of how you can use it:

When your app just loaded

Either stop all tasks:

const tasks = await checkForExistingDownloads()
for (const task of tasks)
  task.stop()

Or re-attach them:

const tasks = await checkForExistingDownloads()
for (const task of tasks) {
  task.pause()
  //
  // YOUR LOGIC OF RE-ATTACHING DOWLOADS TO YOUR STUFF
  // ...
  //
}

Prepare your app to handle downloads... (load your state etc.)
Add listener to handle when your app goes foreground (be sure to do it only after you stopped all tasks or re-attached them!)

function handleAppStateChange (appState) {
  if (appState !== 'active')
    return

  ensureDownloadsAreRunning()
}

const appStateChangeListener = AppState.addEventListener('change', handleAppStateChange)

Call ensureDownloadsAreRunning() after all was setup.

`Callback Methods`

Use these methods to stay updated on what's happening with the task.

All callback methods return the current instance of the DownloadTask for chaining.

Function	Callback Arguments	Info
`begin`	{ expectedBytes, headers }	Called when the first byte is received. 💡: this is good place to check if the device has enough storage space for this download
`progress`	{ bytesDownloaded, bytesTotal }	Called at max every 1.5s so you can update your progress bar accordingly
`done`	{ bytesDownloaded, bytesTotal }	Called when the download is done, the file is at the destination you've set
`error`	{ error, errorCode }	Called when the download stops due to an error

`pause()` (iOS only)

Pauses the download

Note: This functionality is not supported on Android due to limitations in the DownloadManager API. On Android, calling this method will log a warning but will not crash the application.

`resume()` (iOS only)

Resumes a paused download

Note: This functionality is not supported on Android due to limitations in the DownloadManager API. On Android, calling this method will log a warning but will not crash the application.

`stop()`

Stops the download for good and removes the file that was written so far

Constants

directories

`documents`

An absolute path to the app's documents directory. It is recommended that you use this path as the target of downloaded files.

Platform-Specific Limitations

Android DownloadManager Limitations

The Android implementation uses the system's DownloadManager service, which has some limitations compared to iOS:

Pause/Resume Not Supported

Issue: Android's DownloadManager does not provide a public API for pausing and resuming downloads
Impact: Calling task.pause() or task.resume() on Android will log a warning but not perform any action
Workaround: If you need to stop a download, use task.stop() and restart it later with a new download request
Technical Details: The private APIs needed for pause/resume functionality are not accessible to third-party applications

Alternative Approaches for Android

If pause/resume functionality is critical for your application, consider:

Using task.stop() and tracking progress to restart downloads from where they left off (if the server supports range requests)
Implementing a custom download solution for Android that doesn't use DownloadManager
Designing your app flow to minimize the need for pause/resume functionality

Rules for proguard-rules.pro

In case of error java.lang.IllegalStateException: TypeToken must be created with a type argument: new TypeToken<...>() in Android release add this to proguard-rules.pro:

# Application classes that will be serialized/deserialized over Gson
-keep class com.yourapplicationname.model.api.** { *; }

# Gson uses generic type information stored in a class file when working with
# fields. Proguard removes such information by default, keep it.
-keepattributes Signature

# This is also needed for R8 in compat mode since multiple
# optimizations will remove the generic signature such as class
# merging and argument removal. See:
# https://r8.googlesource.com/r8/+/refs/heads/main/compatibility-faq.md#troubleshooting-gson-gson
-keep class com.google.gson.reflect.TypeToken { *; }
-keep class * extends com.google.gson.reflect.TypeToken

# Optional. For using GSON @Expose annotation
-keepattributes AnnotationDefault,RuntimeVisibleAnnotations

TODO

Write better examples - current kinda old and shallow
Write better API for downloads - current kinda boilerplate
Add more tests

Authors

Re-written & maintained by Kesha Antonov

Originally developed by Elad Gil of Eko

License

Apache 2

Name		Name	Last commit message	Last commit date
Latest commit History 247 Commits
.github		.github
.vscode		.vscode
__mocks__		__mocks__
__tests__		__tests__
android		android
example		example
ios		ios
plugin		plugin
src		src
.eslintignore		.eslintignore
.eslintrc.js		.eslintrc.js
.gitattributes		.gitattributes
.gitignore		.gitignore
LICENSE		LICENSE
README.md		README.md
babel.config.js		babel.config.js
metro.config.js		metro.config.js
package.json		package.json
react-native-background-downloader.podspec		react-native-background-downloader.podspec
react-native.config.js		react-native.config.js
yarn.lock		yarn.lock

License

kesha-antonov/react-native-background-downloader

Folders and files

Latest commit

History

Repository files navigation

@kesha-antonov/react-native-background-downloader

Why?

ToC

Getting started

New Architecture Support

Automatic Detection

Manual Setup (Advanced)

Known Issues with New Architecture

Mostly automatic installation

Manual installation

iOS

Android

iOS - Extra Mandatory Step

Option 1: Using Expo Config Plugin (Recommended for Expo/EAS users)

Option 2: Manual Setup

Usage

Downloading a file

Platform-Aware Pause/Resume

Re-Attaching to background downloads

Using custom headers

Handling Slow-Responding URLs

Handling URLs with Many Redirects (Android)

API

RNBackgroundDownloader

download(options)

checkForExistingDownloads()

setConfig({})

DownloadTask

Members

completeHandler(jobId)

ensureDownloadsAreRunning (iOS only)

Callback Methods

pause() (iOS only)

resume() (iOS only)

stop()

Constants

directories

documents

Platform-Specific Limitations

Android DownloadManager Limitations

Pause/Resume Not Supported

Alternative Approaches for Android

Rules for proguard-rules.pro

TODO

Authors

License

About

Resources

License

Uh oh!

Stars

Watchers

Forks

Releases 10

Packages 0

Uh oh!

Contributors 13

Uh oh!

Languages

`download(options)`

`checkForExistingDownloads()`

`setConfig({})`

`Members`

`completeHandler(jobId)`

`ensureDownloadsAreRunning` (iOS only)

`Callback Methods`

`pause()` (iOS only)

`resume()` (iOS only)

`stop()`

`documents`

Packages