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Get Started with Cloud Storage on Android

Cloud Storage for Firebase lets you upload and share user generated content, such as images and video, which allows you to build rich media content into your apps. Your data is stored in a Google Cloud Storage bucket, an exabyte scale object storage solution with high availability and global redundancy. Cloud Storage lets you securely upload these files directly from mobile devices and web browsers, handling spotty networks with ease.

Prerequisites

If you haven't already, add Firebase to your Android project.

Create a default Storage bucket

  1. From the navigation pane of the Firebase console, select Storage, then click Get started.

  2. Review the messaging about securing your Storage data using security rules. During development, consider setting up your rules for public access.

  3. Select a location for your default Storage bucket.

    • This location setting is your project's default Google Cloud Platform (GCP) resource location. Note that this location will be used for GCP services in your project that require a location setting, specifically, your Cloud Firestore database and your App Engine app (which is required if you use Cloud Scheduler).

    • If you aren't able to select a location, then your project already has a default GCP resource location. It was set either during project creation or when setting up another service that requires a location setting.

    If you're on the Blaze plan, you can create multiple buckets, each with its own location.

  4. Click Done.

Set up public access

Cloud Storage for Firebase provides a declarative rules language that allows you to define how your data should be structured, how it should be indexed, and when your data can be read from and written to. By default, read and write access to Storage is restricted so only authenticated users can read or write data. To get started without setting up Authentication, you can configure your rules for public access.

This does make Storage open to anyone, even people not using your app, so be sure to restrict your Storage again when you set up authentication.

Add the Cloud Storage SDK to your app

Using the Firebase Android BoM, declare the dependency for the Cloud Storage Android library in your module (app-level) Gradle file (usually app/build.gradle).

Java

dependencies {
    // Import the BoM for the Firebase platform
    implementation platform('com.google.firebase:firebase-bom:26.1.1')

    // Declare the dependency for the Cloud Storage library
    // When using the BoM, you don't specify versions in Firebase library dependencies
    implementation 'com.google.firebase:firebase-storage'
}

By using the Firebase Android BoM, your app will always use compatible versions of the Firebase Android libraries.

(Alternative) Declare Firebase library dependencies without using the BoM

If you choose not to use the Firebase BoM, you must specify each Firebase library version in its dependency line.

Note that if you use multiple Firebase libraries in your app, we highly recommend using the BoM to manage library versions, which ensures that all versions are compatible.

dependencies {
    // Declare the dependency for the Cloud Storage library
    // When NOT using the BoM, you must specify versions in Firebase library dependencies
    implementation 'com.google.firebase:firebase-storage:19.2.0'
}

Kotlin+KTX

dependencies {
    // Import the BoM for the Firebase platform
    implementation platform('com.google.firebase:firebase-bom:26.1.1')

    // Declare the dependency for the Cloud Storage library
    // When using the BoM, you don't specify versions in Firebase library dependencies
    implementation 'com.google.firebase:firebase-storage-ktx'
}

By using the Firebase Android BoM, your app will always use compatible versions of the Firebase Android libraries.

(Alternative) Declare Firebase library dependencies without using the BoM

If you choose not to use the Firebase BoM, you must specify each Firebase library version in its dependency line.

Note that if you use multiple Firebase libraries in your app, we highly recommend using the BoM to manage library versions, which ensures that all versions are compatible.

dependencies {
    // Declare the dependency for the Cloud Storage library
    // When NOT using the BoM, you must specify versions in Firebase library dependencies
    implementation 'com.google.firebase:firebase-storage-ktx:19.2.0'
}

Set up Cloud Storage

The first step in accessing your storage bucket is to create an instance of FirebaseStorage:

Java

FirebaseStorage storage = FirebaseStorage.getInstance();

Kotlin+KTX

storage = Firebase.storage

You're ready to start using Cloud Storage!

First, let's learn how to create a Cloud Storage reference.

Advanced setup

There are a few use cases that require additional setup:

The first use case is perfect if you have users across the world, and want to store their data near them. For instance, you can create buckets in the US, Europe, and Asia to store data for users in those regions to reduce latency.

The second use case is helpful if you have data with different access patterns. For instance: you can set up a multi-regional or regional bucket that stores pictures or other frequently accessed content, and a nearline or coldline bucket that stores user backups or other infrequently accessed content.

In either of these use cases, you'll want to use multiple storage buckets.

The third use case is useful if you're building an app, like Google Drive, which lets users have multiple logged in accounts (for instance, a personal account and a work account). You can use a custom Firebase App instance to authenticate each additional account.

Use multiple storage buckets

If you want to use a storage bucket other than the default provided above, or use multiple storage buckets in a single app, you can create an instance of FirebaseStorage that references your custom bucket:

Java

// Get a non-default Storage bucket
FirebaseStorage storage = FirebaseStorage.getInstance("gs://my-custom-bucket");

Kotlin+KTX

// Get a non-default Storage bucket
val storage = Firebase.storage("gs://my-custom-bucket")

Working with imported buckets

When importing an existing Cloud Storage bucket into Firebase, you'll have to grant Firebase the ability to access these files using the gsutil tool, included in the Google Cloud SDK:

gsutil -m acl ch -r -u service-<project number>@gcp-sa-firebasestorage.iam.gserviceaccount.com gs://<your-cloud-storage-bucket>

You can find your project number as described in the introduction to Firebase projects.

This does not affect newly created buckets, as those have the default access control set to allow Firebase. This is a temporary measure, and will be performed automatically in the future.

Use a custom Firebase App

If you're building a more complicated app using a custom FirebaseApp, you can create an instance of FirebaseStorage initialized with that app:

Java

// Get the default bucket from a custom FirebaseApp
FirebaseStorage storage = FirebaseStorage.getInstance(customApp);

// Get a non-default bucket from a custom FirebaseApp
FirebaseStorage customStorage = FirebaseStorage.getInstance(customApp, "gs://my-custom-bucket");

Kotlin+KTX

// Get the default bucket from a custom FirebaseApp
val storage = Firebase.storage(customApp!!)

// Get a non-default bucket from a custom FirebaseApp
val customStorage = Firebase.storage(customApp, "gs://my-custom-bucket")

Next steps