S3-compatible storage is the API that AWS S3 defines, and the providers that implement it. The right one depends on the workload, the cost, and the data gravity. The major providers in 2026: AWS S3 (the original), Backblaze B2, Wasabi, Cloudflare R2, MinIO (self-hosted).
Table of contents
- What S3-compatible is
- The providers
- The trade-offs
- When to use AWS S3
- When to use Backblaze B2
- When to use Wasabi
- When to use Cloudflare R2
- When to use MinIO
- FAQ
What S3-compatible is
S3-compatible storage is the API that AWS S3 defines, implemented by other providers. The S3 API is the de facto standard for object storage; the team’s tools, SDKs, and applications work with any S3-compatible provider.
The S3 API defines:
- Buckets. The top-level container for the objects.
- Objects. The files stored in the bucket.
- Keys. The unique identifier for the object within the bucket.
- Operations. GET, PUT, LIST, DELETE, COPY, and the multi-part upload operations.
The providers
The providers in 2026, ordered by adoption:
- AWS S3. The original. The right answer for the team that is on AWS.
- Backblaze B2. The cheapest for storage-heavy workloads. S3-compatible via the S3 API.
- Wasabi. The cheapest for egress-heavy workloads. S3-compatible via the S3 API.
- Cloudflare R2. The cheapest for CDN-paired workloads. S3-compatible via the S3 API.
- MinIO. The self-hosted. The right answer for the team that wants the data on their own infrastructure.
- Ceph. The open-source. The right answer for the team that wants a fully open-source stack.
The trade-offs
The trade-offs the team needs to understand:
- Cost. AWS S3 is the most expensive; the alternatives are 50-80% cheaper.
- Features. AWS S3 has the largest feature set; the alternatives have a smaller subset.
- Performance. AWS S3 has the largest global edge network; the alternatives have regional footprints.
- Vendor lock-in. S3 is the default; the team that switches away is doing a migration project.
When to use AWS S3
The team that should use AWS S3:
- The team that is on AWS.
- The team that needs the full S3 feature set (lifecycle policies, intelligent-tiering, S3 Glacier).
- The team that needs the global edge network.
- The team that does not want to do a migration project.
When to use Backblaze B2
The team that should use Backblaze B2:
- The team that has a storage-heavy workload with light egress.
- The team that wants the cheapest storage cost.
- The team that is willing to operate around the smaller feature set.
When to use Wasabi
The team that should use Wasabi:
- The team that has a storage-heavy workload with heavy egress.
- The team that wants the cheapest egress.
- The team that is willing to operate around the smaller feature set.
When to use Cloudflare R2
The team that should use Cloudflare R2:
- The team that has a workload that benefits from Cloudflare’s CDN.
- The team that wants the cheapest egress.
- The team that is willing to operate around the smaller feature set.
When to use MinIO
The team that should use MinIO:
- The team that wants the data on their own infrastructure.
- The team that has the engineering time to operate a self-hosted object store.
- The team that has a workload with a large storage volume (where the cloud cost is significant).
FAQ
What is S3-compatible storage?
The API that AWS S3 defines, implemented by other providers. The S3 API is the de facto standard for object storage; the team’s tools, SDKs, and applications work with any S3-compatible provider.
What is the cheapest S3-compatible storage in 2026?
Backblaze B2 at $0.006/GB/month and Wasabi at $0.0069/GB/month are the cheapest. Cloudflare R2 at $0.015/GB/month is competitive when paired with the CDN.
Can I use S3 APIs with Backblaze B2 or Wasabi?
Yes. Both are S3-compatible; the team can use the AWS SDK and the standard S3 client tools.
What is the difference between S3 and S3-compatible?
S3 is the AWS implementation. S3-compatible is the API that other providers implement. The two are mostly interchangeable from the team’s perspective.
Should I switch from S3 to a S3-compatible alternative?
If the workload is storage-heavy and egress-light, yes. If the workload needs the full S3 feature set, no. The team should benchmark the migration cost before switching.
If you are sizing the storage tier for a new project, the RunxBuild hosting calculator is the place to model the line items. The storage, the I/O, the egress, the CDN - each one is a separate number, and the team’s mental model for the platform is the sum of those numbers. The RunxBuild dashboard is where the team sees the actual storage usage in one place.