Amazon S3 vs Azure Blob Storage

Updated November 2026 · AppBreakup editorial

Amazon S3

AWS's object storage service, with many storage classes from hot data to deep archive.

Free plan + paid

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Azure Blob Storage

Microsoft Azure's object storage for unstructured data, backups, archives and data lakes.

Paid

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The short answer

Amazon S3 and Azure Blob Storage are the object storage services of the two largest clouds, and the choice usually follows the cloud a team already uses. S3 suits AWS users and anyone relying on the widely copied S3 API; Azure Blob Storage suits organisations built on Microsoft Azure and Entra ID. The biggest practical difference is that Azure Blob is not S3-compatible.

Amazon S3 or Azure Blob Storage: our take

Both services store files as objects, offer tiers from hot to archive, and bill per gigabyte stored, per operation and per gigabyte transferred out, so both can be hard to predict and both have complex pricing tables. The differences are mostly about ecosystem and API.

Amazon S3 defines the API that most other providers copy, so a huge range of tools, SDKs and backup products speak it natively. Its storage classes include Standard, Intelligent-Tiering (which moves objects between tiers automatically), Infrequent Access, Express One Zone and the Glacier archive classes, with Glacier Deep Archive starting from $0.00099 per GB a month. Around storage it adds versioning, cross-region replication, event notifications to serverless functions and integration with nearly every AWS service, and it is designed for 11 nines of durability. New AWS customers get up to $200 in credits.

Azure Blob Storage organises data into storage accounts with five access tiers: Premium, Hot, Cool, Cold and Archive, with lifecycle rules to move data between them. Its strengths are Microsoft-specific: access control through Entra ID and role-based access control, and Data Lake Storage, a hierarchical namespace built on Blob for analytics engines. Reserved capacity can lower costs for large, steady volumes. New accounts get a $200 credit for 30 days. Because it is not S3-compatible, tools written for S3 need adapting.

For a team on AWS, or one that depends on S3-compatible tooling, S3 is the natural choice. For an organisation that manages identity in Entra ID and runs analytics on Azure, Blob Storage fits better. Moving between them is mostly a question of which cloud the rest of the workload lives in.

Choose Amazon S3 if…

Teams building on AWS that need archive tiers, lifecycle rules and deep service integrations
You want a free option (Azure Blob Storage is paid only)
Many storage classes, including automatic tiering and Glacier archives
Integrates with nearly every AWS service

Choose Azure Blob Storage if…

Organisations on Microsoft Azure that want object storage tied into Entra ID and Azure analytics.
Five access tiers from Premium down to Archive
Entra ID and role-based access control built in

What is Amazon S3?

Amazon S3 (Simple Storage Service) is the object storage service from Amazon Web Services and the one whose API most other providers copy. You store files as objects in buckets and access them over the S3 API, SDKs, the AWS console or command line. S3 offers a range of storage classes, from Standard for frequently used data through Intelligent-Tiering, which moves objects between tiers automatically, to Glacier classes for cheap long-term archives. Around storage it adds lifecycle rules, versioning, replication across regions, fine-grained access policies, event notifications to serverless functions and integration with nearly every AWS analytics and AI service. Pricing is pay-as-you-go per gigabyte stored, per request and per gigabyte transferred out, so bills depend heavily on access patterns, and a free tier is available to new AWS accounts. It runs in AWS regions worldwide. It suits teams already on AWS or needing its archive tiers and ecosystem.

What is Azure Blob Storage?

Azure Blob Storage is Microsoft's object storage service, holding files of any kind as blobs inside storage accounts. You choose an access tier per object or account: Premium for low-latency workloads, Hot for frequently used data, Cool and Cold for infrequent access, and Archive for long-term retention at the lowest price, with lifecycle rules moving data between them. Data Lake Storage adds a hierarchical file namespace on top for analytics engines. Access can be controlled with Microsoft Entra ID and role-based access control, and data is encrypted at rest. It is used for app uploads, media, backups, tape replacement and analytics pipelines, and integrates with the rest of Azure. Billing is pay-as-you-go per gigabyte stored, operations and data transfer, with reserved capacity discounts; new accounts can try Azure free for a limited period. It suits organisations already invested in Microsoft's cloud and identity tools.

Side by side

Attribute	Amazon S3	Azure Blob Storage
Pricing	Free plan + paid	Paid
Open source	No	No
Self-hostable	No	No
Platforms	Web	Web
Best for	Teams building on AWS that need archive tiers, lifecycle rules and deep service integrations	Organisations on Microsoft Azure that want object storage tied into Entra ID and Azure analytics.
Status	Active	Active