<br />

Cloud Storage for Firebaselets 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](https://cloud.google.com/storage)bucket --- an exabyte scale object storage solution with high availability and global redundancy.Cloud Storage for Firebaselets you securely upload these files directly from mobile devices and web browsers, handling spotty networks with ease.

## Before you begin

1. If you haven't already, make sure you've completed the[getting started guide for Android apps](https://firebase.google.com/docs/android/setup). This includes:

   - Creating a Firebase project.

   - Registering your Android app with the project, and connecting your app to Firebase by adding the Firebase dependencies, the Google services plugin, and your Firebase config file (`google-services.json`) to your app.

2. Make sure your Firebase project is on the[pay-as-you-go Blaze pricing plan](https://firebase.google.com/pricing), which is a requirement that started in October 2024 (see our[FAQs](https://firebase.google.com/docs/storage/faqs-storage-changes-announced-sept-2024)). If you're new to Firebase and Google Cloud, check if you're eligible for a[$300 credit](https://firebase.google.com/support/faq#pricing-free-trial).

## Create a defaultCloud Storagebucket

1. From the navigation pane of the[Firebaseconsole](https://console.firebase.google.com/), select**Storage**.

   If your project is not yet on the pay-as-you-go Blaze pricing plan, then you'll be prompted to upgrade your project.
2. Click**Get started**.

3. Select a[location](https://firebase.google.com/docs/storage/locations)for your default bucket.

   - Buckets in`US-CENTRAL1`,`US-EAST1`, and`US-WEST1`can take advantage of the["Always Free" tier](https://cloud.google.com/storage/pricing#cloud-storage-always-free)forGoogle Cloud Storage. Buckets in all other locations follow[Google Cloud Storagepricing and usage](https://cloud.google.com/storage/pricing).

   - If you'd like, you can later[create multiple buckets](https://firebase.google.com/docs/storage/android/start#use_multiple_storage_buckets), each with its own location.

4. Configure theFirebase Security Rulesfor your default bucket. During development, consider[setting up your rules for public access](https://firebase.google.com/docs/storage/android/start#set_up_public_access).

5. Click**Done**.

You can now view the bucket in the[Cloud Storage*Files*tab](https://console.firebase.google.com/project/_/storage/)of theFirebaseconsole. Your default bucket name format is<var translate="no">PROJECT_ID</var>`.firebasestorage.app`.
| **Note:** StartingOctober 30, 2024, all new defaultCloud Storagebuckets have the name format<var translate="no">PROJECT_ID</var>`.firebasestorage.app`. Any default buckets created*before* that date have the name format<var translate="no">PROJECT_ID</var>`.appspot.com`. Learn more in the[FAQs](https://firebase.google.com/docs/storage/faqs-storage-changes-announced-sept-2024#all-changes-default-storage-bucket).

## Set up public access

Cloud Storage for Firebaseprovides a declarative rules language that lets you 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 toCloud Storageis restricted so only authenticated users can read or write data. To get started without setting up[Authentication](https://firebase.google.com/docs/auth), you can[configure your rules for public access](https://firebase.google.com/docs/storage/security/rules-conditions#public).

This does makeCloud Storageopen to anyone, even people not using your app, so be sure to restrict yourCloud Storageagain when you set up authentication.

## Add theCloud StorageSDK to your app

In your**module (app-level) Gradle file** (usually`<project>/<app-module>/build.gradle.kts`or`<project>/<app-module>/build.gradle`), add the dependency for theCloud Storagelibrary for Android. We recommend using the[Firebase Android BoM](https://firebase.google.com/docs/android/learn-more#bom)to control library versioning.

<br />

```carbon
dependencies {
    // Import the BoM for the Firebase platform
    implementation(platform("com.google.firebase:firebase-bom:34.6.0"))

    // Add 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](https://firebase.google.com/docs/android/learn-more#bom), your app will always use compatible versions of Firebase Android libraries.
*(Alternative)* Add Firebase library dependencies*without* using theBoM

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

**Note that if you use*multiple* Firebase libraries in your app, we strongly recommend using theBoMto manage library versions, which ensures that all versions are compatible.**  

```groovy
dependencies {
    // Add 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:22.0.1")
}
```

<br />

## Set upCloud Storagein your app

1. Make sure the Firebase config file (`google-services.json`) in your app's codebase is updated with the name of your defaultCloud Storagebucket.

   1. [Obtain your updated config file.](https://support.google.com/firebase/answer/7015592#android).

   2. Use this downloaded config file to*replace* the existing`google-services.json`file in your app's module (app-level) directory.

      Make sure that you only have this most recent downloaded config file in your app and that its filename isn't appended with additional characters, like`(2)`.

   | **Note:** Alternatively to replacing your config file, you can explicitly specify the bucket name when you create an instance of`FirebaseStorage`(see next step). You can find the bucket name in the[Cloud Storage*Files*tab](https://console.firebase.google.com/project/_/storage/)of theFirebaseconsole.
2. Access yourCloud Storagebucket by creating an instance of`FirebaseStorage`:

   ### Kotlin

   <br />

   ```kotlin
   storage = Firebase.storage  
   https://github.com/firebase/snippets-android/blob/294e0edf389e04ad85622081afb988aed37c20fb/storage/app/src/main/java/com/google/firebase/referencecode/storage/kotlin/StorageActivity.kt#L37-L37
   ```  

   ```kotlin
   // Alternatively, explicitly specify the bucket name URL.
   // val storage = Firebase.storage("gs://<var translate="no">BUCKET_NAME</var>")
   ```

   <br />

   ### Java

   <br />

   ```java
   FirebaseStorage storage = FirebaseStorage.getInstance();https://github.com/firebase/snippets-android/blob/294e0edf389e04ad85622081afb988aed37c20fb/storage/app/src/main/java/com/google/firebase/referencecode/storage/StorageActivity.java#L66-L66
   ```  

   ```java
   // Alternatively, explicitly specify the bucket name URL.
   // FirebaseStorage storage = FirebaseStorage.getInstance("gs://<var translate="no">BUCKET_NAME</var>");
   ```

   <br />

You're ready to start usingCloud Storage!

Next step? Learn how to[create aCloud Storagereference](https://firebase.google.com/docs/storage/android/create-reference).

## Advanced setup

There are a few use cases that require additional setup:

- UsingCloud Storagebuckets in[multiple geographic regions](https://cloud.google.com/storage/docs/bucket-locations)
- UsingCloud Storagebuckets in[different storage classes](https://cloud.google.com/storage/docs/storage-classes)
- UsingCloud Storagebuckets with multiple authenticated users in the same app

The first use case is perfect if you have users across the world, and want to store their data near them. For example, 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 example: 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 multipleCloud Storagebuckets](https://firebase.google.com/docs/storage/android/start#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](https://firebase.google.com/docs/storage/android/start#use_a_custom_firebaseapp)instance to authenticate each additional account.

### Use multipleCloud Storagebuckets

If you want to use aCloud Storagebucket other than the default bucket described earlier in this guide, or use multipleCloud Storagebuckets in a single app, you can create an instance of`FirebaseStorage`that references your custom bucket:  

### Kotlin

```kotlin
// Get a non-default Storage bucket
val storage = Firebase.storage("gs://my-custom-bucket")https://github.com/firebase/snippets-android/blob/294e0edf389e04ad85622081afb988aed37c20fb/storage/app/src/main/java/com/google/firebase/referencecode/storage/kotlin/StorageActivity.kt#L418-L419
```

### Java

```java
// Get a non-default Storage bucket
FirebaseStorage storage = FirebaseStorage.getInstance("gs://my-custom-bucket");https://github.com/firebase/snippets-android/blob/294e0edf389e04ad85622081afb988aed37c20fb/storage/app/src/main/java/com/google/firebase/referencecode/storage/StorageActivity.java#L538-L539
```

### Working with imported buckets

When importing an existingCloud Storagebucket into Firebase, you'll have to grant Firebase the ability to access these files using the`gsutil`tool, included in the[Google CloudSDK](https://cloud.google.com/sdk/docs/):  

```
gsutil -m acl ch -r -u service-PROJECT_NUMBER@gcp-sa-firebasestorage.iam.gserviceaccount.com gs://BUCKET_NAME
```

You can find your project number as described in the[introduction to Firebase projects](https://firebase.google.com/docs/projects/learn-more#project-number).

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:  

### Kotlin

```kotlin
// 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")https://github.com/firebase/snippets-android/blob/294e0edf389e04ad85622081afb988aed37c20fb/storage/app/src/main/java/com/google/firebase/referencecode/storage/kotlin/StorageActivity.kt#L427-L431
```

### Java

```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");https://github.com/firebase/snippets-android/blob/294e0edf389e04ad85622081afb988aed37c20fb/storage/app/src/main/java/com/google/firebase/referencecode/storage/StorageActivity.java#L547-L551
```

## Next steps

- Prepare to launch your app:

  - Enable[App Check](https://firebase.google.com/docs/app-check/android)to help ensure that only your apps can access your storage buckets.

  - Set up[budget alerts](https://firebase.google.com/docs/projects/billing/avoid-surprise-bills#set-up-budget-alert-emails)for your project in theGoogle Cloudconsole.

  - Monitor the[*Usage and billing*dashboard](https://console.firebase.google.com/project/_/usage)in theFirebaseconsole to get an overall picture of your project's usage across multiple Firebase services. You can also visit the[Cloud Storage*Usage*dashboard](https://console.firebase.google.com/project/_/storage/usage)for more detailed usage information.

  - Review the[Firebase launch checklist](https://firebase.google.com/support/guides/launch-checklist).