Make data public

This page shows you how to make objects you own readable to everyone on the public internet. To learn how to access data that has been made public, see Accessing Public Data .

When an object is shared publicly, any user with knowledge of the object URI can access the object for as long as the object is public.

Required roles

In order to get the required permissions for making objects publicly readable, ask your administrator to grant you the following roles for the bucket that contains the data you want to make public:

  • To make all objects in a bucket publicly readable: Storage Admin ( roles/storage.admin )

  • To make individual objects publicly readable: Storage Object Admin ( roles/storage.objectAdmin )

    • If you plan on using the Google Cloud console, you'll need the Storage Admin ( roles/storage.admin ) role instead of the Storage Object Admin role.

These roles contain the permissions required to make objects public. To see the exact permissions that are required, expand the Required permissionssection:

Required permissions

  • storage.buckets.get
  • storage.buckets.getIamPolicy
  • storage.buckets.setIamPolicy
  • storage.buckets.update
  • storage.objects.get
  • storage.objects.getIamPolicy
  • storage.objects.setIamPolicy
  • storage.objects.update

The following permissions are only required for using the Google Cloud console to perform the tasks on this page:

  • storage.buckets.list
  • storage.objects.list

You might also be able to get these permissions with other predefined roles or custom roles .

For instructions on granting roles on buckets, see Use IAM with buckets .

Make all objects in a bucket publicly readable

To make all objects in a bucket readable to everyone on the public internet, grant the principal allUsers the Storage Object Viewer ( roles/storage.objectViewer ) role:

Console

  1. In the Google Cloud console, go to the Cloud Storage Buckets page.

    Go to Buckets

  2. In the list of buckets, click the name of the bucket that you want to make public.

  3. Select the Permissionstab near the top of the page.

  4. In the Permissionssection, click the Grant accessbutton.

    The Grant access dialog appears.

  5. In the New principalsfield, enter allUsers .

  6. In the Select a roledrop down, enter Storage Object Viewer in the filter box and select the Storage Object Viewerfrom the filtered results.

  7. Click Save.

  8. Click Allow public access.

Once public access has been granted, Copy URLappears for each object in the public access column. You can click this button to get the public URL for the object.

To learn how to get detailed error information about failed Cloud Storage operations in the Google Cloud console, see Troubleshooting .

Command line

  1. In the Google Cloud console, activate Cloud Shell.

    Activate Cloud Shell

    At the bottom of the Google Cloud console, a Cloud Shell session starts and displays a command-line prompt. Cloud Shell is a shell environment with the Google Cloud CLI already installed and with values already set for your current project. It can take a few seconds for the session to initialize.

  2. In your development environment, run the buckets add-iam-policy-binding command:

    gcloud storage buckets add-iam-policy-binding gs:// BUCKET_NAME 
    --member=allUsers --role=roles/storage.objectViewer

    Where BUCKET_NAME is the name of the bucket whose objects you want to make public. For example, my-bucket .

Client libraries

C++

For more information, see the Cloud Storage C++ API reference documentation .

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

 namespace gcs = ::google::cloud::storage;
using ::google::cloud::StatusOr;
[](gcs::Client client, std::string const& bucket_name) {
  auto current_policy = client.GetNativeBucketIamPolicy(
      bucket_name, gcs::RequestedPolicyVersion(3));
  if (!current_policy) throw std::move(current_policy).status();

  current_policy->set_version(3);
  current_policy->bindings().emplace_back(
      gcs::NativeIamBinding("roles/storage.objectViewer", {"allUsers"}));

  auto updated =
      client.SetNativeBucketIamPolicy(bucket_name, *current_policy);
  if (!updated) throw std::move(updated).status();

  std::cout << "Policy successfully updated: " << *updated << "\n";
} 

C#

For more information, see the Cloud Storage C# API reference documentation .

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

 using Google.Apis.Storage.v1.Data;
using Google.Cloud.Storage.V1;
using System;
using System.Collections.Generic;

public class MakeBucketPublicSample
{
    public void MakeBucketPublic(string bucketName = "your-unique-bucket-name")
    {
        var storage = StorageClient.Create();

        Policy policy = storage.GetBucketIamPolicy(bucketName);

        policy.Bindings.Add(new Policy.BindingsData
        {
            Role = "roles/storage.objectViewer",
            Members = new List<string> { "allUsers" }
        });

        storage.SetBucketIamPolicy(bucketName, policy);
        Console.WriteLine(bucketName + " is now public ");
    }
} 

Go

For more information, see the Cloud Storage Go API reference documentation .

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

 import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/iam"
	"cloud.google.com/go/iam/apiv1/iampb"
	"cloud.google.com/go/storage"
)

// setBucketPublicIAM makes all objects in a bucket publicly readable.
func setBucketPublicIAM(w io.Writer, bucketName string) error {
	// bucketName := "bucket-name"
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %w", err)
	}
	defer client.Close()

	policy, err := client.Bucket(bucketName).IAM().V3().Policy(ctx)
	if err != nil {
		return fmt.Errorf("Bucket(%q).IAM().V3().Policy: %w", bucketName, err)
	}
	role := "roles/storage.objectViewer"
	policy.Bindings = append(policy.Bindings, &iampb.Binding{
		Role:    role,
		Members: []string{iam.AllUsers},
	})
	if err := client.Bucket(bucketName).IAM().V3().SetPolicy(ctx, policy); err != nil {
		return fmt.Errorf("Bucket(%q).IAM().SetPolicy: %w", bucketName, err)
	}
	fmt.Fprintf(w, "Bucket %v is now publicly readable\n", bucketName)
	return nil
} 

Java

For more information, see the Cloud Storage Java API reference documentation .

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

 import com.google.cloud.Identity;
import com.google.cloud.Policy;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import com.google.cloud.storage.StorageRoles;

public class MakeBucketPublic {
  public static void makeBucketPublic(String projectId, String bucketName) {
    // The ID of your GCP project
    // String projectId = "your-project-id";

    // The ID of your GCS bucket
    // String bucketName = "your-unique-bucket-name";

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    Policy originalPolicy = storage.getIamPolicy(bucketName);
    storage.setIamPolicy(
        bucketName,
        originalPolicy
            .toBuilder()
            .addIdentity(StorageRoles.objectViewer(), Identity.allUsers()) // All users can view
            .build());

    System.out.println("Bucket " + bucketName + " is now publicly readable");
  }
} 

Node.js

For more information, see the Cloud Storage Node.js API reference documentation .

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

 /**
 * TODO(developer): Uncomment the following lines before running the sample.
 */
// The ID of your GCS bucket
// const bucketName = 'your-unique-bucket-name';

// Imports the Google Cloud client library
const {Storage} = require('@google-cloud/storage');

// Creates a client
const storage = new Storage();

async function makeBucketPublic() {
  await storage.bucket(bucketName).makePublic();

  console.log(`Bucket ${bucketName} is now publicly readable`);
}

makeBucketPublic().catch(console.error); 

PHP

For more information, see the Cloud Storage PHP API reference documentation .

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

 use Google\Cloud\Storage\StorageClient;

/**
 * Update the specified bucket's IAM configuration to make it publicly accessible.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 *        (e.g. 'my-bucket')
 */
function set_bucket_public_iam(string $bucketName): void
{
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);

    $policy = $bucket->iam()->policy(['requestedPolicyVersion' => 3]);
    $policy['version'] = 3;

    $role = 'roles/storage.objectViewer';
    $members = ['allUsers'];

    $policy['bindings'][] = [
        'role' => $role,
        'members' => $members
    ];

    $bucket->iam()->setPolicy($policy);

    printf('Bucket %s is now public', $bucketName);
} 

Python

For more information, see the Cloud Storage Python API reference documentation .

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

 from typing import List

from google.cloud import storage


def set_bucket_public_iam(
    bucket_name: str = "your-bucket-name",
    members: List[str] = ["allUsers"],
):
    """Set a public IAM Policy to bucket"""
    # bucket_name = "your-bucket-name"

    storage_client = storage.Client()
    bucket = storage_client.bucket(bucket_name)

    policy = bucket.get_iam_policy(requested_policy_version=3)
    policy.bindings.append(
        {"role": "roles/storage.objectViewer", "members": members}
    )

    bucket.set_iam_policy(policy)

    print(f"Bucket {bucket.name} is now publicly readable") 

Ruby

For more information, see the Cloud Storage Ruby API reference documentation .

To authenticate to Cloud Storage, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

 def set_bucket_public_iam bucket_name:
  # The ID of your GCS bucket
  # bucket_name = "your-unique-bucket-name"

  require "google/cloud/storage"

  storage = Google::Cloud::Storage.new
  bucket = storage.bucket bucket_name

  bucket.policy do |p|
    p.add "roles/storage.objectViewer", "allUsers"
  end

  puts "Bucket #{bucket_name} is now publicly readable"
end