Integrates Firebase Cloud Storage into Flutter apps. Use when setting up Storage, uploading or downloading files, managing metadata, handling errors, or applying security rules.
This skill defines how to correctly use Firebase Cloud Storage in Flutter applications.
Use this skill when:
flutter pub add firebase_storage
import 'package:firebase_storage/firebase_storage.dart';
final storage = FirebaseStorage.instance;
// Or specify a bucket explicitly:
// final storage = FirebaseStorage.instanceFor(bucket: "gs://BUCKET_NAME");
flutterfire configure to update your Firebase config with the default Storage bucket name.Security note: By default, a Cloud Storage bucket requires Firebase Authentication for any action. Configuring public access may also make App Engine files publicly accessible — restrict access again when you set up Authentication.
Create a reference:
final storageRef = FirebaseStorage.instance.ref();
final fileRef = storageRef.child("uploads/file.jpg");
Upload:
final uploadTask = fileRef.putFile(file);
final snapshot = await uploadTask;
final downloadUrl = await snapshot.ref.getDownloadURL();
Download (in-memory):
final data = await fileRef.getData();
Download URL:
final downloadUrl = await fileRef.getDownloadURL();
Delete:
await fileRef.delete();
Get metadata:
final metadata = await fileRef.getMetadata();
print('Content type: ${metadata.contentType}');
print('Size: ${metadata.size}');
Update metadata:
final newMetadata = SettableMetadata(
contentType: "image/jpeg",
customMetadata: {'uploaded_by': 'user123'},
);
await fileRef.updateMetadata(newMetadata);
Use custom metadata to store additional key/value pairs with your files.
Use try-catch with FirebaseException. Key error codes:
| Code | Meaning |
|---|---|
storage/object-not-found | File doesn't exist at the reference |
storage/bucket-not-found | No bucket configured for Cloud Storage |
storage/project-not-found | No project configured for Cloud Storage |
storage/quota-exceeded | Storage quota exceeded |
storage/unauthenticated | User needs to authenticate |
storage/unauthorized | User lacks permission |
storage/retry-limit-exceeded | Operation timeout exceeded |
quota-exceeded on the Spark plan, upgrade to Blaze.Monitor upload progress:
final uploadTask = fileRef.putFile(file);
uploadTask.snapshotEvents.listen((TaskSnapshot snapshot) {
print('Progress: ${(snapshot.bytesTransferred / snapshot.totalBytes) * 100}%');
});
uploadTask.cancel().uploadTask.pause() and uploadTask.resume().