Download files

There are three ways of getting data that was previously uploaded:

Download File

You can download file to a local directory using Amplify.Storage.downloadFile.

You can use the path_provider package to create a local file in the user's documents directory where you can store the downloaded data.

import 'package:amplify_flutter/amplify_flutter.dart';
import 'package:path_provider/path_provider.dart';
Future<void> downloadFile() async {
  final documentsDir = await getApplicationDocumentsDirectory();
  final filepath = '${documentsDir.path}/example.txt';
    final result = await Amplify.Storage.downloadFile(
      path: const StoragePath.fromString('public/example.txt'),
      localFile: AWSFile.fromPath(filepath),
    ).result;
    safePrint('Downloaded file is located at: ${result.localFile.path}');
  } on StorageException catch (e) {
    safePrint(e.message);

On Web, the download process will be handled by the browser. You can provide the downloaded file name by specifying the path parameter of AWSFile.fromPath. E.g. this instructs the browser to download the file download.txt.

import 'package:amplify_flutter/amplify_flutter.dart';
Future<void> downloadFile() async {
    final result = await Amplify.Storage.downloadFile(
      path: const StoragePath.fromString('public/example.txt'),
      localFile: AWSFile.fromPath('download.txt'),
    ).result;
    safePrint('Downloaded file: ${result.downloadedItem.path}');
  } on StorageException catch (e) {
    safePrint(e.message);

Download data

You can download a file to in-memory buffer with Amplify.Storage.downloadData:

Future<void> download() async {
    final result = await Amplify.Storage.downloadData(
      path: const StoragePath.fromString('public/example.txt'),
    ).result;
    safePrint('Downloaded data: ${result.bytes}');
  } on StorageException catch (e) {
    safePrint(e.message);

Download Progress

To track progress of the download, use the progress listener callback.

final operation = Amplify.Storage.downloadFile(
  localFile: AWSFile.fromPath('/path/to/local/file.txt'),
  path: const StoragePath.fromString('public/example.txt'),
  onProgress: (progress) {
    safePrint('fraction totalBytes: ${progress.totalBytes}');
    safePrint('fraction transferredBytes: ${progress.transferredBytes}');
    safePrint('fraction completed: ${progress.fractionCompleted}');

final operation = Amplify.Storage.downloadData(
  path: const StoragePath.fromString('public/example.txt'),
  onProgress: (progress) {
    safePrint('fraction totalBytes: ${progress.totalBytes}');
    safePrint('fraction transferredBytes: ${progress.transferredBytes}');
    safePrint('fraction completed: ${progress.fractionCompleted}');

Control of Download Operations

A call to Amplify.Storage.downloadFile or Amplify.Storage.downloadData returns a reference to the operation that is performing the upload.

To cancel the upload (for example, in response to the user pressing a Cancel button), simply call .cancel() on the returned upload operation. Download operations also allows for the operation to be paused and resumed.

Future<void> download() async {
  final operation = Amplify.Storage.downloadFile(
    localFile: AWSFile.fromPath('/path/to/local/file.txt'),
    path: const StoragePath.fromString('public/example.txt'),
  // pause operation
  await operation.pause();
  // resume operation
  await operation.resume();
  // cancel operation
  await operation.cancel();

Future<void> download() async {
  final operation = Amplify.Storage.downloadData(
    path: const StoragePath.fromString('public/example.txt'),
  // pause operation
  await operation.pause();
  // resume operation
  await operation.resume();
  // cancel operation
  await operation.cancel();

Generate a download URL

You can get a downloadable URL for the file in storage by its path.

When creating a downloadable URL, you can choose to check if the file exists by setting validateObjectExistence to true in S3GetUrlPluginOptions. If the file is inaccessible or does not exist, a StorageException is thrown. This allows you to check if an object exists during generating the presigned URL, which you can then use to download that object.

Future<void> getDownloadUrl() async {
    final result = await Amplify.Storage.getUrl(
      path: const StoragePath.fromString('public/example.txt'),
      options: const StorageGetUrlOptions(
        pluginOptions: S3GetUrlPluginOptions(
          validateObjectExistence: true,
          expiresIn: Duration(days: 1),
    ).result;
    safePrint('url: ${result.url}');
  } on StorageException catch (e) {
    safePrint(e.message);

Upload files

Get file properties