# Google Cloud Storage GUI client for Mac, iPhone, and Web

> A Google Cloud Storage GUI with folder downloads and folder rename, using HMAC keys. GCS pricing, storage classes, and S3 error fixes.

Canonical: https://www.bucketmate.app/s3-client/google-cloud-storage

Google Cloud Storage accepts S3-style requests with HMAC keys. BucketMate uses that path so GCS sits next to your other buckets.

Best for: Teams on Google Cloud that want storage-class control

## Google Cloud Storage at a glance (checked October 2026)

- **Standard**: $0.020/GB - per month in us-central1
- **Egress**: $0.12/GB - to the internet, first 10 TiB
- **Always Free**: 5 GB - in us-west1, us-central1, us-east1
- **Cold classes**: 30-365 days - minimums for Nearline to Archive
- Pricing: https://cloud.google.com/storage/pricing

## Google Cloud Storage console vs BucketMate

| Task | Console | BucketMate |
| --- | --- | --- |
| Download a folder | One object at a time. Use gcloud | Download folders or the whole bucket |
| Rename a folder | Only in hierarchical namespace buckets | Rename folders in any bucket |
| Upload a folder | Chrome only | Drag folders in from Finder |

## Made for Google Cloud Storage

- **Storage classes**: See and change Standard, Nearline, Coldline, and Archive per file. BucketMate shows the minimum duration first.
- **Soft delete**: GCS keeps deleted objects 7 days by default, and bills for them. Check the bucket's soft delete setting.
- **HMAC keys**: Create HMAC keys for a service account. They're separate from JSON keys and can be revoked any time.

## Common errors

- `SignatureDoesNotMatch`: Wrong HMAC secret, or a region other than auto or us-east-1. Fix: Re-copy the secret and keep the endpoint https://storage.googleapis.com.
- `does not have storage.objects.list access`: The service account lacks list permission on the bucket. Fix: Grant a role with storage.objects.list, like Storage Object Viewer.
- `UserProjectMissing`: The bucket is Requester Pays. Fix: Set a default project on the Interoperability tab.
- `400 on ACL calls`: Uniform bucket-level access is on, so ACLs are rejected. Fix: Use IAM, or switch the bucket to fine-grained access.

## Endpoint

`https://storage.googleapis.com`

Use the global endpoint for the best compatibility.


## Connect in BucketMate

A Cloud Storage HMAC access ID and secret.

1. Create an HMAC key for a service account in Cloud Storage interoperability settings.
2. In BucketMate, choose Add connection and select Google Cloud Storage.
3. Enter https://storage.googleapis.com, the HMAC keys, and the bucket location, then Test Connection.

On iPhone, Google Cloud Storage has its own option with the endpoint prefilled.

## S3 compatibility notes

- **HMAC keys only**: Service account JSON keys do not work for S3 access.
- **Org policies**: restrictAuthTypes can block HMAC keys in your organization.
- **5 MiB parts**: Multipart parts must be at least 5 MiB.

## FAQ

### Can I use an S3 client with Google Cloud Storage?

Yes, with HMAC keys through the GCS XML API. BucketMate does this on macOS, iOS, and Web.

### How do I download a folder from Google Cloud Storage?

The console downloads one object at a time and points you to gcloud for folders. BucketMate downloads folders and whole buckets.

### How much does Google Cloud Storage cost?

Standard is about $0.020 per GB per month in us-central1. Internet egress starts at $0.12 per GB. Always Free covers 5 GB in three US regions.

### Can I use a service account JSON key?

No. Create an HMAC key for the service account instead.

### Does BucketMate send my GCS keys to a server?

No. Keys stay on your device and requests go straight to Google.

## Links

- Docs: https://docs.bucketmate.app/macos/providers/connect-google-cloud-storage.md
- Download: https://www.bucketmate.app/download
- Web app: https://web.bucketmate.app/
- All providers: https://www.bucketmate.app/s3-client.md