Backblaze B2

What Backblaze B2 actually is

Backblaze B2 is budget object storage with an S3-compatible API, and it is the clearest price story in our cloud object storage category. Backblaze announced the service in September 2015, opened the public beta that December, and shipped 1.0 with its 99.9% SLA shortly after — built on the same home-grown storage hardware (the open-source Storage Pods and the Vault architecture) that powers its consumer backup business. A Vault spreads each object across 20 storage pods as 20 shards, and the company publishes its durability math openly: 11 nines (99.999999999%) annual durability, with one internal calculation actually coming out to 12 nines. Few competitors show their arithmetic.

The API story is two-sided. There is a native B2 API, and there is an S3-Compatible API that implements the commonly used S3 actions and works with AWS SDKs and the S3 CLI by overriding the endpoint. Buckets are versioned by default, server-side encryption is available with Backblaze-managed keys (SSE-B2) or customer keys (SSE-C), and the S3-compatible endpoint supports IPv6. The documented differences from real S3 are worth reading before you migrate: ACLs are bucket-level with only "private" and "public-read", object tagging and IAM roles are not supported on the S3 API, and an account belongs to exactly one region — you cannot create buckets outside your account's region.

That last point matters more than it sounds. Backblaze runs four regions across six data centers: US West (Sacramento and Phoenix; Stockton also stores US-West data per the subprocessor list), US East (Reston, Virginia), EU Central (Amsterdam, Netherlands), and Canada East (Toronto). The region is fixed at account creation. For EU data residency — which our old listing claimed was missing — Amsterdam has covered that since 2019. Cloud Replication can copy data between regions using separate accounts.

Pricing: what you really pay

The headline changed recently and our database needed updating: storage is now $6.95 per TB per month, raised from the long-standing $6/TB effective May 1, with existing committed contracts unchanged until renewal. That is $0.00695/GB — roughly a quarter of AWS S3 standard storage and Azure Hot. Billing is by byte-hour, with no minimum file size and no minimum storage duration fees, which quietly matters: S3-compatible budget rivals often add 90-day early-deletion penalties, and B2 does not.

Egress is the other half of the value story, and the current policy is better than the old "free with Cloudflare" framing our listing used. Every B2 account gets free egress up to 3x its average monthly storage (calculated on byte-hours across the billing cycle), and anything above that is a flat, published $0.01/GB. Additionally, egress is unlimited and free to partner CDN and compute providers — Cloudflare, Fastly, bunny.net, CacheFly, CoreWeave, Equinix Metal, Vultr, and phoenixNAP. For comparison, S3's published egress is $0.09/GB.

Transactions are now effectively free too: API calls (Class A, B, C) carry no charge as of the May pricing update. Class D calls (downloads, some list operations) cost $0.004 per 10,000 after 2,500 free per day. The free tier is permanent: the first 10 GB of storage is free, along with the egress allowance and daily Class D allowance. At the top end, B2 Overdrive starts at $15/TB/month with unlimited free egress and dedicated vaults, aimed at multi-petabyte customers, and B2 Neo serves neocloud-scale buyers on negotiated terms.

In our view this is the most predictable object storage bill in the market. The one number to watch is the 3x egress ratio: a workload that downloads far more than it stores — video distribution, public datasets — should model the $0.01/GB overage or front the bucket with a partner CDN.

Performance & infrastructure

Six data centers in four regions is a small footprint next to AWS or Azure, and it is the honest trade: you are not buying global distribution, you are buying cheap, durable capacity in one place. Within a region, the Vault architecture (20 pods, 20 shards, rebuild-on-failure) is engineered for durability rather than latency. Practically, we'd expect strong sequential throughput and good behavior for backup, archive, media pipelines, and snapshot storage, especially from European or North American origins; we have no benchmark runs of our own against B2, so treat throughput claims — ours or Backblaze's — as things to verify with your own transfer patterns.

The availability picture is stated plainly. Backblaze's SLA sets a 99.9% monthly uptime objective with a service-credit table of 5% below 99.9% and 10% below 99.0%. Compare that with hyperscaler SLAs offering 99.9% availability with 10–100% credits: Backblaze's credit ladder is weak, and we say so. The SLA also excludes scheduled maintenance windows and requires customers to follow the published integration checklist. The compensating fact is track record — B2 has been running since 2015-2016 at substantial scale (the company claims over 500,000 customers across 175 countries, which is a vendor figure) and publishes infrastructure details most vendors keep private.

On the operations side: CLI, web UI, native REST API, S3-compatible API, integrations with the usual backup tooling (Veeam, MSP360, rclone, Synology and QNAP apps), and Cloud Replication between regions. Lifecycle rules cover version management and hiding old versions.

Where it falls short

Regionality first. One region per account, no cross-region buckets, no read replicas, and no CDN of your own — if you need global low-latency distribution, you pair B2 with Cloudflare or Fastly (where egress is free) or you buy a different product. Moving an account to another region means creating a new account and copying data.

The S3-compatible API is a compatibility layer, not parity. No IAM roles, no object tagging, no website configuration, bucket-level ACLs only, SSE-KMS unsupported. Most backup and data tools run fine; anything exotic around S3 policies or object metadata should be tested before commitment.

SLA compensation is thin (5%/10% credits against a 99.9% objective), and support beyond the standard tier is where Backblaze historically drew the line — the SLA itself only extends to Computer Backup customers on paid support plans for that product, while all B2 customers are covered. Enterprise expectations around private networking, compliance attestations, and dedicated vaults land in B2 Overdrive/Reserve territory, not self-serve.

Finally, this is storage only. No compute, no functions, no database — anything dynamic runs elsewhere.

The company culture around pricing deserves a mention because it is part of the product. Backblaze has published its storage pod costs, its drive failure rates (the famous hard drive stats posts), and the durability calculation behind the 11-nines number. That habit of showing the arithmetic is why we trust the price sheet: when a vendor explains how it gets to a claim, the claims that go unexplained are easier to weigh. In a market where budget providers often hide fair-use clauses, a flat $0.01/GB egress overage with no penalties is a meaningful signal.

Who should pick this

We pick B2 when the job is storing a lot of bytes cheaply and predictably: backup targets, snapshot archives, media and asset libraries, data-lake cold layers, and the storage half of self-hosted stacks. For European buyers, the Amsterdam region settles the old data-residency objection, and it is our budget pick in cloud object storage for anyone whose egress stays within the 3x allowance or goes through a partner CDN. Teams already using backup solutions — Veeam, rclone, NAS apps — will find it is the default target for a reason.

We would not pick it for global low-latency delivery (use a CDN or a hyperscaler), for workloads that need S3 parity (IAM, tagging, replication rules), or for read-heavy distributions that exceed 3x stored volume without a partner CDN. And if you need storage, compute, and identity under one enterprise agreement, the hyperscalers still bundle better — at multiples of the price.

Key takeaways

• Object storage at $6.95/TB/month (raised from $6/TB in May; committed contracts unchanged), billed by byte-hour with no minimum file size or duration fees.
• Free egress up to 3x average monthly storage for everyone, unlimited free egress to partners (Cloudflare, Fastly, Vultr, and others), $0.01/GB flat above that.
• S3-compatible API (plus a native API), IPv6 support, versioned buckets, SSE-B2/SSE-C encryption — but no IAM roles, object tagging, or S3 website hosting.
• Four regions, six data centers — including Amsterdam (EU Central) and Toronto — with the region fixed at account creation.
• 11 nines claimed durability (published Vault math) behind a modest 99.9% uptime SLA with 5–10% service credits.
• Our budget pick for backup, archive, and asset storage; wrong tool for global delivery or full S3 parity.

Sources

• https://backblaze.com/cloud-storage/pricing
• https://backblaze.com/b2/cloud-storage-pricing.html
• https://backblaze.com/blog/backblaze-pricing-and-product-updates
• https://www.backblaze.com/docs/en/cloud-storage-data-regions
• https://www.backblaze.com/company/policy/sla
• https://www.backblaze.com/company/policy/subprocessors
• https://www.backblaze.com/docs/cloud-storage-resiliency-durability-and-availability
• https://backblaze.com/blog/cloud-storage-durability
• https://backblaze.com/blog/b2-cloud-storage-provider
• https://backblaze.com/blog/b2-cloud-storage-public-beta
• https://backblaze.com/apidocs/introduction-to-the-s3-compatible-api
• https://backblaze.com/docs/cloud-storage-s3-compatible-api
• https://help.backblaze.com/hc/en-us/articles/360034360834-EU-Region-FAQ
• https://f004.backblazeb2.com/file/devweek-2026-collateral/Backblaze+B2+IaaS+Solution+.pdf
• https://egresscost.com/backblaze-b2