# Amazon S3 vs Azure Blob Storage: which do AI models recommend for object storage, October 2026

IT AI Recommendation Index, October 2026 Edition, Object storage. Three of fourteen models named Amazon S3 first on the direct prompt; one named Azure Blob Storage. Page: https://it-ai-index.com/cloud/object-storage/amazon-s3-vs-azure-blob-storage/

| | First-choice share | Rank | Negative rate | Labels | Models naming it |
|---|---|---|---|---|---|
| Amazon S3 | 12% | #3 of 9 | 34% | 67 | 14 of 14 |
| Azure Blob Storage | 6% | #5 of 9 | 31% | 42 | 13 of 14 |

## The direct prompt, model by model

- MiniMax M2.5: both first (first choices: Amazon S3, Azure Blob Storage) (alternatives: Backblaze B2, Google Cloud Storage, Wasabi Object Storage)
- GPT-5.4 mini: amazon s3 first (first choices: Amazon S3) (alternatives: Azure Blob Storage, Google Cloud Storage)
- GPT-6 Luna: amazon s3 first (first choices: Amazon S3) (alternatives: Azure Blob Storage, Cloudflare R2, Google Cloud Storage)
- Perplexity Sonar: neither first, one named (first choices: Google Cloud Storage) (alternatives: Amazon S3, Backblaze B2, Wasabi Object Storage)
- Mistral Small: neither first, one named (first choices: Backblaze B2) (alternatives: Amazon S3, Cloudian HyperStore)
- DeepSeek V4 Flash: neither first, one named (first choices: Backblaze B2) (alternatives: Amazon S3, Cloudflare R2)
- Kimi K2: neither first, one named (first choices: Cloudflare R2) (alternatives: Azure Blob Storage, Backblaze B2, Google Cloud Storage)
- GLM 4.7 FlashX: neither first, one named (first choices: Backblaze B2) (alternatives: Amazon S3, Cloudflare R2, MinIO AIStor, Wasabi Object Storage)
- Muse Glimmer 30B: neither first, one named (alternatives: Amazon S3, Backblaze B2, Cloudflare R2, Wasabi Object Storage)
- Claude Haiku 4.5: neither named
- Gemini 3.5 Flash: neither named (first choices: Cloudflare R2) (alternatives: Backblaze B2, Wasabi Object Storage)
- Grok 4.1 Fast: neither named (first choices: Backblaze B2) (alternatives: Cloudflare R2, Wasabi Object Storage)
- Llama 4 Maverick: neither named
- Qwen 3.7 Flash: neither named (first choices: Backblaze B2, Wasabi Object Storage)

## What the models said about Amazon S3

- "Avoid hyperscalers (AWS/GCP/Azure) on tight budgets due to egress/API add-ons." (Grok 4.1 Fast, budget prompt, hard negative)
- "Traditional hyperscalers like AWS S3 are incredibly powerful but often punish growing mid-sized companies with unpredictable API transaction fees and steep "egress taxes"" (Gemini 3.5 Flash, paraphrase prompt, soft negative)
- "Be cautious if… You're comparing only the per-GB storage price. Requests, retrievals, transfers, replication, and archive-tier rules can also affect the bill" (GPT-6 Luna, negative prompt, soft negative)
- "Best for: Enterprise workloads, S3-native applications... AWS S3, Azure Blob, and GCS offer the most comprehensive feature sets" (GLM 4.7 FlashX, comparative prompt, first choice)
- "If you want one answer without more context: choose Amazon S3 unless your company is already standardized on Azure or GCP." (GPT-5.4 mini, direct prompt, first choice)
- "The industry standard. Most third-party tools default to S3 compatibility because it has the largest ecosystem" (Qwen 3.7 Flash, comparative prompt, first choice)

## What the models said about Azure Blob Storage

- ""avoid or be cautious about ... those with high egress fees or minimum retention periods, such as GCS and Azure Cold"" (Muse Glimmer 30B, negative prompt, hard negative)
- "Avoid hyperscalers (AWS/GCP/Azure) on tight budgets due to egress/API add-ons." (Grok 4.1 Fast, budget prompt, hard negative)
- "High egress fees (e.g., AWS S3: $0.09/GB after free tier; GCS/Azure similar) lead to unpredictable bills and vendor lock-in" (Grok 4.1 Fast, negative prompt, soft negative)
- "Start with AWS S3 or Azure Blob — native integration, massive ecosystem, but watch egress costs." (DeepSeek V4 Flash, scale prompt, first choice)
- "I'd recommend Amazon S3 or Azure Blob Storage due to their enterprise-grade security" (MiniMax M2.5, direct prompt, first choice)
- "Check AWS S3 / Azure Blob: If you are already deep in one ecosystem." (Qwen 3.7 Flash, scale prompt, first choice)

Share is the count of first choices across the direct, paraphrase, budget and scale prompts over all fourteen models, for a mid-market B2B company; rank is within the category. Comparisons are drawn for the top eight products in each category. Published under CC BY 4.0; the output is the models' output, and nothing here is a recommendation by the index.