Backblaze

B2 supports both the native B2 API and the S3-compatible API. The native B2 API offers bucket management, file upload/download (including large file multipart), URL generation, and lifecycle rules. The S3 compatibility layer supports the most common S3 operations — PUT, GET, DELETE, list buckets/objects, multipart upload — enabling drop-in replacement for S3-based tooling. Agents using `@aws-sdk/client-s3` or similar can point to B2's S3 endpoint with B2 credentials.

Backblaze B2 is an S3-compatible cloud object storage service offering storage at a fraction of AWS S3's price — typically 75-80% cheaper for both storage ($0.006/GB vs ~$0.023/GB) and egress. The S3-compatible API means agents and applications using any S3 client library can switch to B2 with a URL and credential change, without code modifications. For storage-heavy workloads where S3 costs are significant, B2 provides comparable reliability at a substantially lower price point.

Authentication uses application keys with configurable bucket and prefix permissions. The key model is more granular than AWS IAM for common use cases — agents can create keys scoped to specific buckets or prefixes without building IAM policies. Keys support duration limits for time-bounded access.

Documentation covers both the native B2 API and S3 compatibility, with clear guidance on client library configuration. The S3 compatibility matrix — documenting which S3 API operations are supported — is essential for teams evaluating a migration. Teams comparing Backblaze B2 versus Cloudflare R2 for S3 alternatives should also evaluate R2's zero-egress pricing (advantageous for high-download workloads) against B2's broader geographic availability.

Reliability is production-grade — Backblaze's storage durability claim is 99.999999999% (11 nines), comparable to S3 Standard. The infrastructure runs from multiple US and EU datacenters. Teams migrating from S3 should verify that any S3 features they use are supported in B2's S3 compatibility layer before switching.