Handle errors for Cloud Storage on Android

Sometimes things don't go as planned and an error occurs.

When in doubt, check the error returned and see what the error message says. The following code shows a custom error handler implementation that inspects the error code and error message returned by Cloud Storage. Such error handlers can be added to various objects used in the Cloud Storage API (for example, UploadTask and FileDownloadTask).

Kotlin+KTX

internal inner class MyFailureListener : OnFailureListener {
    override fun onFailure(exception: Exception) {
        val errorCode = (exception as StorageException).errorCode
        val errorMessage = exception.message
        // test the errorCode and errorMessage, and handle accordingly
    }
}
StorageActivity.kt

Java

class MyFailureListener implements OnFailureListener {
    @Override
    public void onFailure(@NonNull Exception exception) {
        int errorCode = ((StorageException) exception).getErrorCode();
        String errorMessage = exception.getMessage();
        // test the errorCode and errorMessage, and handle accordingly
    }
}
StorageActivity.java

If you've checked the error message and have Cloud Storage Security Rules that allow your action, but are still struggling to fix the error, visit our Support page and let us know how we can help.

Handle Error Messages

There are a number of reasons why errors may occur, including the file not existing, the user not having permission to access the desired file, or the user cancelling the file upload.

To properly diagnose the issue and handle the error, here is a full list of all the errors our client will raise, and how they can occur. Error codes in this table are defined in the StorageException class as integer constants.

Code	Reason
ERROR_UNKNOWN	An unknown error occurred.
ERROR_OBJECT_NOT_FOUND	No object exists at the specified reference.
ERROR_BUCKET_NOT_FOUND	No bucket is configured for Cloud Storage
ERROR_PROJECT_NOT_FOUND	No project is configured for Cloud Storage
ERROR_QUOTA_EXCEEDED	Quota on your Cloud Storage bucket has been exceeded. If you're on the Spark pricing plan, consider upgrading to the pay-as-you-go Blaze pricing plan. If you're already on the Blaze pricing plan, reach out to Firebase Support. Important: Starting October 1, 2025, the Blaze pricing plan will be required to use Cloud Storage, even default buckets.
ERROR_NOT_AUTHENTICATED	User is unauthenticated, please authenticate and try again.
ERROR_NOT_AUTHORIZED	User is not authorized to perform the requested action, check your rules to ensure they are correct.
ERROR_RETRY_LIMIT_EXCEEDED	The maximum time limit on an operation (upload, download, delete, etc.) has been excceded. Try again.
ERROR_INVALID_CHECKSUM	File on the client does not match the checksum of the file received by the server. Try uploading again.
ERROR_CANCELED	User canceled the operation.

Additionally, attempting to call getReferenceFromUrl() with an invalid URL will result in an IllegalArgumentException from being thrown. The argument to the above method must be of the form gs://bucket/object or https://firebasestorage.googleapis.com/v0/b/bucket/o/object?token=<TOKEN>