Object storage
Amazon S3 vs Azure Blob Storage
The Azure equivalent of Amazon S3 is Azure Blob Storage.
Both store objects in flat containers (S3 buckets, Blob containers) with an HTTP API, multiple cost tiers, versioning, replication, and WORM locking.
Side-by-side comparison
| Aspect | Amazon Web Services | Microsoft Azure |
|---|---|---|
| Service | Amazon S3 | Azure Blob Storage |
| Lifecycle | Generally available | Generally available |
| What it is | Object storage in buckets, with 11 nines of durability, a choice of storage classes, versioning, replication, Object Lock, and fine-grained IAM and bucket policies. General purpose buckets hold any object type; directory, table, and vector buckets are specialized bucket types. | Object storage in containers inside a storage account. Block, append, and page blobs, with LRS, ZRS, GRS, GZRS, and read-access geo options, versioning, soft delete, and Entra ID, SAS, or account-key authorization. |
| Pricing model | Per GB-month by storage class, plus per-request charges, retrieval fees for IA and Glacier classes, and data transfer out. | Per GB-month by access tier and redundancy option, plus per-10,000-operation charges, retrieval fees for cool, cold, and archive, geo-replication data transfer for GRS/GZRS, and data transfer out. |
| Docs | Amazon S3 docs | Azure Blob Storage docs |
| Pricing page | Amazon S3 pricing | Azure Blob Storage pricing |
| Exams | CLF-C02 SAA-C03 SOA-C03 SAP-C02 Retiring | AZ-900 AZ-104 AZ-305 |
Key differences
- Account model. S3 buckets are top-level resources with globally unique names. Blob containers live inside a storage account, and the account sets the redundancy, default access tier, network rules, and some features (such as the hierarchical namespace) for every container in it.
- Redundancy. S3 Standard stores data across at least three AZs by default; One Zone classes and Express One Zone use a single AZ. On Azure you choose per account. LRS is a single datacenter, ZRS spans zones, and GRS/GZRS add an asynchronous copy in the paired region. Pick ZRS explicitly if you want S3-like zone resilience.
- Object types. S3 has one object type (with multipart upload). Blob Storage has block blobs (the S3 equivalent), append blobs (for logs), and page blobs (random-access, used by legacy unmanaged disks).
- Bucket types. S3 also has directory buckets (Express One Zone), table buckets (S3 Tables), and vector buckets (S3 Vectors). Azure gets the equivalent features from premium block blob accounts, Fabric OneLake, and Azure AI Search.
- Consistency. Both offer strong read-after-write consistency for objects in the primary region.
Pricing summary
Pricing models only. No prices are quoted because they change by region and over time.
- AWS
- Per GB-month by storage class, plus per-request charges, retrieval fees for IA and Glacier classes, and data transfer out. Amazon S3 pricing →
- Azure
- Per GB-month by access tier and redundancy option, plus per-10,000-operation charges, retrieval fees for cool, cold, and archive, geo-replication data transfer for GRS/GZRS, and data transfer out. Azure Blob Storage pricing →
Certification exam mapping
| Exam | Provider | Level | Status |
|---|---|---|---|
| AWS Certified Cloud Practitioner CLF-C02 | AWS | Foundational | current Italian and German versions retire after Dec 31, 2026. |
| AWS Certified Solutions Architect – Associate SAA-C03 | AWS | Associate | current Italian version retires after Dec 31, 2026. |
| AWS Certified CloudOps Engineer – Associate SOA-C03 | AWS | Associate | current Replaces AWS Certified SysOps Administrator – Associate (SOA-C02), whose last exam day was Sep 29, 2025. Simplified Chinese and Korean versions retire after Nov 19, 2026. |
| AWS Certified Solutions Architect – Professional SAP-C02 | AWS | Professional | retiring Being updated to SAP-C03. Registration for SAP-C03 opens Oct 27, 2026. Last day to take SAP-C02 is Nov 16, 2026. |
| Microsoft Certified – Azure Fundamentals AZ-900 | Azure | Fundamentals | current |
| Microsoft Certified – Azure Administrator Associate AZ-104 | Azure | Associate | current |
| Microsoft Certified – Azure Solutions Architect Expert AZ-305 | Azure | Expert | current English version updated Apr 17, 2026. |
Relevance is based on each exam's published scope, not a line-by-line objective match. Check the official study guide.
FAQ
What is the Azure equivalent of Amazon S3?
The Azure equivalent of Amazon S3 is Azure Blob Storage. Both store objects in flat containers (S3 buckets, Blob containers) with an HTTP API, multiple cost tiers, versioning, replication, and WORM locking.
How does pricing compare between Amazon S3 and Azure Blob Storage?
AWS: Per GB-month by storage class, plus per-request charges, retrieval fees for IA and Glacier classes, and data transfer out. Azure: Per GB-month by access tier and redundancy option, plus per-10,000-operation charges, retrieval fees for cool, cold, and archive, geo-replication data transfer for GRS/GZRS, and data transfer out. Check the official pricing pages for current rates.
Which certification exams cover this topic?
AWS Certified Cloud Practitioner (CLF-C02); AWS Certified Solutions Architect – Associate (SAA-C03); AWS Certified CloudOps Engineer – Associate (SOA-C03); AWS Certified Solutions Architect – Professional (SAP-C02) [retiring]; Microsoft Certified – Azure Fundamentals (AZ-900); Microsoft Certified – Azure Administrator Associate (AZ-104); Microsoft Certified – Azure Solutions Architect Expert (AZ-305).
What is the Azure equivalent of an S3 bucket?
A Blob Storage container. Bucket-level settings such as redundancy, firewall, and encryption defaults mostly live on the storage account that holds the container, so many AWS teams create one storage account per workload or data classification.
Is Azure Blob Storage as durable as S3?
It depends on the redundancy you choose. Microsoft documents at least 11 nines of annual durability for LRS, 12 nines for ZRS, and 16 nines for GRS and GZRS. S3 Standard is designed for 11 nines across multiple AZs.