Backblaze B2 vs Cloudflare R2

Backblaze B2 and Cloudflare R2 are the two leading low-cost alternatives to AWS S3, and both have competed aggressively by eliminating or dramatically reducing egress fees — the cost that makes S3 expensive for read-heavy, publicly served workloads. Understanding the difference between them requires examining their egress cost structures, storage pricing, S3 API compatibility depth, geographic distribution, reliability track records, and total cost of ownership across different workload profiles.

Egress Cost Structure: Free vs Near-Free

Cloudflare R2 has zero egress fees. Data transferred from R2 to the internet, to Cloudflare Workers, or via Cloudflare CDN is completely free. This is a structural guarantee — R2's pricing model is built without egress charges at any volume level.

Backblaze B2 charges $0.01 per GB for egress in the general case. However, B2 has a formal partnership with Cloudflare: data egress from Backblaze B2 to Cloudflare's network is free, including transfers to Cloudflare CDN, Cloudflare Workers, and Cloudflare Pages. For applications using Cloudflare's CDN in front of Backblaze B2 storage — a very common pattern for static sites, media delivery, and software distribution — the effective egress cost is also $0.

In practice, this B2 + Cloudflare CDN combination matches R2's egress economics for most web-served content. The difference matters for non-CDN use cases: direct B2 downloads from external servers, server-to-server transfers outside Cloudflare's network, or downloads from client applications that bypass CDN. In these scenarios, B2 charges $0.01/GB while R2 remains free.

Storage Pricing: B2's Structural Advantage

Backblaze B2 charges $0.006 per GB per month — the lowest storage price among major object storage providers with a strong operational track record. The first 10GB of storage is free permanently.

Cloudflare R2 charges $0.015 per GB per month — 2.5x more expensive than B2 for stored bytes. For storage-heavy workloads — large media archives, video libraries, backup storage, software distribution mirrors — B2's cost advantage compounds. A 100TB video archive costs approximately $600/month on B2 versus $1,500/month on R2 — a $900/month difference that represents 10,800/year purely from storage cost. For storage-dominated workloads where egress is minimal, B2 is substantially cheaper.

S3 API Compatibility

Cloudflare R2 has made S3 API compatibility a core design principle. R2's S3-compatible endpoint covers all core operations — PutObject, GetObject, DeleteObject, ListObjectsV2, HeadObject, CopyObject, CreateMultipartUpload/UploadPart/CompleteMultipartUpload, presigned URL generation (GET and PUT), and CORS configuration. Any S3 SDK can communicate with R2 by changing the endpoint URL and credentials with no code changes. The compatibility is deep and reliable.

Backblaze B2 offers both its native B2 API and an S3-compatible endpoint. The S3-compatible API covers the core operations and works with most S3 SDKs — the AWS SDK v2, v3, Boto3, and rclone all function correctly with B2's S3-compatible endpoint. Some behavioral edge cases differ from S3 (lifecycle rule syntax, some ACL behaviors, bucket policy support), and Backblaze has been progressively improving compatibility over time. For standard use cases — upload, download, list, delete, presigned URLs — B2's S3-compatible endpoint works well. Applications that rely on advanced S3 features (complex lifecycle transitions, server-side encryption with customer keys, object versioning, event notifications) require more careful validation.

Reliability and Operational Track Record

Backblaze B2 has operated since 2015 and stores over an exabyte of customer data across its infrastructure. Backblaze builds and operates its own data centers in Sacramento, CA and Amsterdam, NL, giving it a different operational profile than cloud-provider-hosted storage — you're trusting Backblaze's hardware and operations rather than AWS, Google, or Azure infrastructure. B2 replicates data across servers within each facility. Backblaze publishes quarterly hard drive failure reports, demonstrating unusual transparency about their infrastructure. B2 has a 99.9% uptime SLA and high durability — specific durability numbers are not published at S3's 11-nines level, but Backblaze's track record over nine years of B2 operation is strong.

Cloudflare R2 stores data across Cloudflare's distributed infrastructure with automatic redundancy. Cloudflare's operational track record for CDN and DNS is excellent, and R2 inherits that infrastructure foundation. R2 is newer (publicly available since 2022) with less longitudinal history than B2. For mission-critical, compliance-sensitive, or irreplaceable data where maximum historical reliability evidence matters, B2's longer track record provides more confidence data.

Geographic Distribution

Cloudflare R2's key advantage in geographic distribution is that reads are automatically routed through Cloudflare's 300+ PoP network. A user in Singapore requesting an R2 object gets served from a Cloudflare PoP in Singapore — consistent global read latency without CDN configuration. R2 doesn't currently offer region selection (data placement is managed by Cloudflare) — important for data residency compliance requirements in jurisdictions with strict localization rules.

Backblaze B2 currently offers two regions: US West (Sacramento) and EU Central (Amsterdam). For GDPR-compliant data storage, the EU region provides geographic compliance. For globally distributed applications needing consistent low-latency reads across Asia-Pacific, South America, or other regions, Cloudflare R2 + CDN provides broader geographic coverage out of the box.

SDK and Tooling Ecosystem

R2 works with all major S3-compatible SDKs and tooling. Cloudflare's Wrangler CLI provides R2 management commands and local development simulation. R2's native Workers binding enables zero-HTTP-overhead reads from Cloudflare Workers — `const object = await env.MY_BUCKET.get(key)` with sub-millisecond latency. This tight Workers integration enables patterns impossible with any other storage backend.

B2 provides its own CLI (`b2`) and official Python SDK, plus S3-compatible endpoints for use with any S3 tooling. Rclone has first-class B2 support via both native and S3-compatible modes. The AWS CLI, Terraform's Cloudflare provider (for R2) and the generic AWS S3 Terraform resource (for B2 with S3-compatible config) both work.

Migration Path

B2-to-R2 or R2-to-B2 migrations are technically straightforward due to both services' S3 API compatibility. A standard migration flow: configure rclone with both source and destination credentials, run `rclone sync` to copy objects, update your application's endpoint URL and credentials, validate in staging, then switch production traffic. The main migration risk is validating that any advanced S3 features your application uses (lifecycle rules, event notifications, CORS configurations) are equivalently supported in the destination.

Choose Backblaze B2 for cost-optimized archival storage where per-GB storage price is the primary optimization (lowest storage pricing available), for workloads using Cloudflare CDN where the free egress partnership eliminates data transfer costs, or for backup use cases where access frequency is low and storage cost dominates. Choose Cloudflare R2 for zero-egress workloads outside the Cloudflare CDN partnership, Cloudflare Workers-integrated applications where native R2 binding performance provides architectural advantages, or new projects where Cloudflare's edge network distribution provides globally consistent read performance without CDN configuration overhead.