How to configure Cloudflare R2?

Choose 'Cloudflare' as the provider, fill in your Access Key R2, Secret Key, leave the region as 'auto' and indicate the endpoint provided in your Cloudflare dashboard.

Does it support local MinIO servers?

Select 'MinIO' and enter the IP address and port of your server (eg: http://nas.local:9000).

Object Storage (S3)IAM & API access keys

Amazon S3 & S3-Compatible

The Ultimate S3 Bucket Manager for AWS, MinIO, Wasabi, Cloudflare R2 and Ceph

Download Ultra Explorer

Overview of Amazon S3 & S3-Compatible Integration

One S3 connector covers AWS and compatible services such as Cloudflare R2, Wasabi, Scaleway, DigitalOcean Spaces, MinIO and Ceph. Buckets open like folders in the dual-pane explorer.

AWS and S3-compatible providers, or self-hosted MinIO and Ceph
Multipart uploads with adjustable chunk size and concurrency
Recursive folder and bucket sizes

In-App Configuration Dialog

Capture Amazon S3 & S3-Compatible — Ultra Explorer — S3 configuration in Ultra Explorer: full compatibility with AWS, Cloudflare R2, MinIO, Scaleway and Wasabi.

How to connect Amazon S3 & S3-Compatible in Ultra Explorer

Choose Amazon S3

Select "Amazon S3 & S3-compatible storage" in Ultra Explorer provider list.
Select Object Storage Provider

Choose your vendor (AWS, Wasabi, Cloudflare R2, MinIO, Ceph, Scaleway, DigitalOcean, etc.).
Enter IAM / API Access Keys

Paste your Access Key ID and Secret Access Key (or leave blank if using instance IAM role or env vars).
Region and Endpoint URL

Specify the bucket region and endpoint URL if using alternative S3 services (e.g. Cloudflare R2, MinIO).
Advanced Options and Connect

Toggle advanced options if needed (Path Style mode for MinIO, chunk size) then click "Connect and verify".

Configuration fields

Storage Name

Required

name= AWS S3

Unique identifier for this storage remote in Ultra Explorer (e.g. gdrive-perso, backup-s3).Default value: AWS S3

S3 Provider

Optional

provider= AWS

Optional. Choose your Object Storage provider: AWS, MinIO, Wasabi, Cloudflare R2, DigitalOcean Spaces, Ceph, Backblaze B2, Scaleway, OVHcloud, Google Cloud Storage, or Other.Default value: AWS

Access Key ID

Optional

access_key_id

Optional if environment variables or IAM instance roles are active. Required for direct authentication: your S3 access key ID.

Secret Access Key

Optional

secret_access_key

Optional if environment variables or IAM instance roles are active. Required for direct authentication: secret key paired with your Access Key ID.

Region

Optional

region= us-east-1

Optional. Datacenter region (e.g. us-east-1, eu-west-3, or 'auto' for Cloudflare R2).Default value: us-east-1

Endpoint URL

Optional

endpoint

Optional for official AWS S3. REQUIRED for third-party S3 or MinIO (e.g. https://<account_id>.r2.cloudflarestorage.com or http://192.168.1.100:9000).

Location Constraint

Optional

location_constraint

Optional. Geographic constraint required by certain providers when creating new buckets. Must match the Region.

Default Permissions (Canned ACL)

Optional

acl= private

Optional. Canned ACL applied by default when creating buckets and uploading objects (e.g. private, public-read, bucket-owner-full-control).Default value: private

Server-Side Encryption (SSE)

Optional

server_side_encryption

Optional. At-rest encryption algorithm applied when storing objects in S3 (e.g. AES256, aws:kms).

KMS Key ARN

Optional

sse_kms_key_id

Optional. Required only if server-side encryption is set to 'aws:kms'. Enter the full ARN of your AWS KMS key.

Default Storage Class

Optional

storage_class= STANDARD

Optional. Default storage class for newly uploaded objects (e.g. STANDARD, STANDARD_IA, GLACIER, DEEP_ARCHIVE, INTELLIGENT_TIERING).Default value: STANDARD

Bucket Object Lock

Optional

bucket_object_lock_enabled= false

Optional. Enables WORM (Write Once Read Many) object locking when creating new buckets.Default value: false

Force Path Style

Optional Advanced Option

force_path_style= false

Optional (Advanced). Access buckets as endpoint/bucket instead of bucket.endpoint. Required for MinIO and private S3 gateways.Default value: false

Force Legacy v2 Auth

Optional Advanced Option

v2_auth= false

Optional (Advanced). Enables S3 v2 signatures for legacy servers incompatible with AWS Signature Version 4.Default value: false

Multipart Chunk Size

Optional Advanced Option

chunk_size= 5Mi

Optional (Advanced). Chunk size for multipart uploads. Increase to accelerate large file transfers over fast networks.Default value: 5Mi

Upload Concurrency

Optional Advanced Option

upload_concurrency= 4

Optional (Advanced). Number of parts of the same large file uploaded simultaneously in parallel.Default value: 4

Disable Checksums

Optional Advanced Option

disable_checksum= false

Optional (Advanced). Disables MD5/SHA256 checksum computation to maximize upload speeds on reliable networks.Default value: false

Frequently Asked Questions about Amazon S3 & S3-Compatible

Choose 'Cloudflare' as the provider, fill in your Access Key R2, Secret Key, leave the region as 'auto' and indicate the endpoint provided in your Cloudflare dashboard.
Select 'MinIO' and enter the IP address and port of your server (eg: http://nas.local:9000).