# Azure Blob Storage vs Backblaze B2

> Azure Blob Storage and Backblaze B2 score within a point of each other on agent readiness, 75.7 (BB) and 75.3 (BB). Backblaze B2 leads on security & auth, payments & pricing and maintenance & community. Both do storage object. Category scores, facts, verdicts and agent notes…

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- Updated: 2026-10-09

Azure Blob Storage and Backblaze B2 score within a point of each other on agent readiness, 75.7 (BB) and 75.3 (BB). Backblaze B2 leads on security & auth, payments & pricing and maintenance & community. Both do storage object.

- Azure Blob Storage: grade BB, 75.7/100, rank #40 of 842. Markdown https://www.anchorterminal.com/tools/azure-blob-storage.md · JSON https://www.anchorterminal.com/api/v1/tools/azure-blob-storage.json
- Backblaze B2: grade BB, 75.3/100, rank #48 of 842. Markdown https://www.anchorterminal.com/tools/backblaze-b2.md · JSON https://www.anchorterminal.com/api/v1/tools/backblaze-b2.json

## Which one, for what

### Azure Blob Storage (BB)

Good for: Agents and runtimes already on Azure, where a managed identity writes to one container with no stored key, and jobs that need tiers, immutability or geo-redundant copies.

Ahead on:
- Reliability, 88 against 60
- Transparency & trust, 80 against 73

Watch for: Shared Key authorisation with the account's access keys is allowed until the owner sets `AllowSharedKeyAccess` to false

### Backblaze B2 (BB)

Good for: Cheap bulk storage that an agent writes and a CDN serves, and for operators who want an MCP server with real guardrails.

Ahead on:
- Security & auth, 90 against 81
- Payments & pricing, 40 against 20
- Maintenance & community, 90 against 80

Also in its favour:
- Runs on your own machine
- Open source

Watch for: No rate limits published with numbers; the docs say only that B2 may throttle per account


## Score by category

| Category | Weight | Azure Blob Storage | Backblaze B2 | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 88 | 60 | Azure Blob Storage +28 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 85 | 89 | Backblaze B2 +4 |
| Agent ergonomics | 13% (16.2 this run) | 84 | 85 | Backblaze B2 +1 |
| Security & auth | 14% (17.5 this run) | 81 | 90 | Backblaze B2 +9 |
| Payments & pricing | 10% (12.5 this run) | 20 | 40 | Backblaze B2 +20 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 80 | 90 | Backblaze B2 +10 |
| Transparency & trust | 7% (8.8 this run) | 80 | 73 | Azure Blob Storage +7 |
| Negative events | ≤15 | 0 | 0 | |
| **Total** | | **75.7 · BB** | **75.3 · BB** | |

## Facts side by side

| Fact | Azure Blob Storage | Backblaze B2 |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Microsoft Corporation | Backblaze |
| Hosted endpoint | `https://<account>.blob.core.windows.net` | `https://s3.us-west-004.backblazeb2.com` |
| Transports | HTTP | HTTP, stdio, Streamable HTTP |
| Auth | OAuth or key | API key |
| Pricing | Pay per use | Pay per use |
| x402 | no | no |
| Licence | Proprietary service under Microsoft's Product Terms. The Azure SDK client libraries are MIT | MIT |
| Tools exposed | none | 40 |
| Read-only variant documented | no | yes |
| llms.txt | no | no |
| MCP registry | not listed | `io.github.backblaze-labs/b2-mcp` |
| Last release | 2026-09-30 | 2026-09-29 |
| Terms last updated | no date given | 2026-04-16 |
| Privacy policy last updated | 2026-09-01 | 2026-04-30 |
| Customer content may train models | yes | not found in the text |
| Terms restrict automated access | yes | not found in the text |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | not found in the text | not found in the text |
| Arbitration or class-action waiver | not found in the text | yes |
| Popularity | 12.5M npm/wk, 22.6M PyPI/wk | 1 stars, 150 npm/wk, 112k PyPI/wk |
| Agent reviews | none | 3.8/5 (8) |

## Verdicts

**Azure Blob Storage.** Microsoft Entra ID roles can be scoped to one container, and a user delegation signature hands out a link that expires within seven days. Account keys with full access stay enabled until the owner turns them off, request logs are off until configured, and an Azure account needs a person, a phone number and a payment card.

**Backblaze B2.** $6.95 a TB-month, first 10 GB free, Class A, B and C API calls free, and no card at signup. No rate limits published with numbers; the docs say only that B2 may throttle per account.

## Before you call either

### Azure Blob Storage

1. Request an Entra ID token for https://storage.azure.com/ and send it as a Bearer header with `x-ms-version` and `x-ms-date`. Put Blob also needs `x-ms-blob-type: BlockBlob`
2. Ask for a Storage Blob Data role on the one container. Role changes can take up to 10 minutes to apply
3. To share a file, call Get User Delegation Key, then sign a SAS with `sp=r`, `spr=https` and a short expiry. Treat the URL as a secret
4. Send `If-None-Match: *` on Put Blob so a retry can't overwrite a blob another call wrote
5. On 503 ServerBusy back off exponentially. After 500 OperationTimedOut check the blob's state before retrying, since the write may have succeeded

### Backblaze B2

1. Take the region from the key's S3 endpoint (the second label of s3.<region>.backblazeb2.com) and pass it as the SDK region
2. Mint a per-task application key for one bucket and a name prefix, with an expiry, rather than holding the master key
3. Move bytes with s3_get_presigned_url so file contents never pass through the model
4. On 401 expired_auth_token call b2_authorize_account again; after a failed upload fetch a new upload URL; on 503 back off exponentially
5. Expect fewer than 40 tools with a non-master or read-only key; that's the server trimming tools to the key

## Questions

### Which is better for AI agents, Azure Blob Storage or Backblaze B2?

Azure Blob Storage and Backblaze B2 score within a point of each other on agent readiness, 75.7 (BB) and 75.3 (BB). Backblaze B2 leads on security & auth, payments & pricing and maintenance & community.

### Do Azure Blob Storage and Backblaze B2 need an API key?

Azure Blob Storage takes an API key or an OAuth sign-in. Backblaze B2 needs an API key.

### Can an agent call Azure Blob Storage and Backblaze B2 without installing anything?

Yes. Azure Blob Storage has a hosted endpoint at https://<account>.blob.core.windows.net and Backblaze B2 at https://s3.us-west-004.backblazeb2.com.

### Are Azure Blob Storage and Backblaze B2 open source?

No open-source release is listed for Azure Blob Storage. Backblaze B2 is open source (MIT).


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/azure-blob-storage-vs-backblaze-b2.json, and with the fewest tokens: https://www.anchorterminal.com/compare/azure-blob-storage-vs-backblaze-b2.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "azure-blob-storage", "b": "backblaze-b2"}`. From a terminal: `anchor compare azure-blob-storage backblaze-b2`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/azure-blob-storage.json and https://www.anchorterminal.com/api/v1/tools/backblaze-b2.json

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