S3 Storage Classes

Amazon S3 offers a range of storage classes designed for different use cases. Choosing the right storage class can dramatically reduce your storage costs while maintaining the durability and availability your workload requires.

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Overview of Storage Classes

Storage Class	Use Case	Durability	Availability	Min Storage Duration	Retrieval Fee
S3 Standard	Frequently accessed data	99.999999999%	99.99%	None	None
S3 Intelligent-Tiering	Unknown or changing access patterns	99.999999999%	99.9%	None	None
S3 Standard-IA	Infrequently accessed, rapid retrieval	99.999999999%	99.9%	30 days	Per GB
S3 One Zone-IA	Infrequent access, single AZ is acceptable	99.999999999%	99.5%	30 days	Per GB
S3 Glacier Instant Retrieval	Archive with millisecond access	99.999999999%	99.9%	90 days	Per GB
S3 Glacier Flexible Retrieval	Archive, minutes to hours retrieval	99.999999999%	99.99% (after restore)	90 days	Per GB
S3 Glacier Deep Archive	Long-term archive, 12-hour retrieval	99.999999999%	99.99% (after restore)	180 days	Per GB

All storage classes provide the same eleven 9s of durability. The differences lie in availability, retrieval time, and cost.

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S3 Standard

The default and most widely used storage class.

• Best for: Frequently accessed data — websites, content distribution, big data analytics, mobile and gaming applications.
• Availability: 99.99% (designed).
• Replication: Data is stored across a minimum of 3 Availability Zones.
• Pricing: Highest storage cost per GB, but no retrieval fees.

If you are unsure which class to use, start with Standard.

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S3 Intelligent-Tiering

The hands-off optimisation class. S3 Intelligent-Tiering automatically moves objects between access tiers based on actual usage patterns.

How It Works

Tier	Access Pattern	Transition
Frequent Access	Recently or regularly accessed	Default tier on upload
Infrequent Access	Not accessed for 30 days	Automatic
Archive Instant Access	Not accessed for 90 days	Automatic
Archive Access	Not accessed for 90-180 days	Optional, configurable
Deep Archive Access	Not accessed for 180+ days	Optional, configurable

• No retrieval fees when objects are moved between tiers.
• A small monthly monitoring and automation fee per object.
• Best for: Data with unknown, unpredictable, or changing access patterns.

Enable Intelligent-Tiering on upload:

aws s3 cp data.csv s3://my-bucket/data.csv --storage-class INTELLIGENT_TIERING

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S3 Standard-IA (Infrequent Access)

Designed for data that is accessed less frequently but requires rapid retrieval when needed.

• Best for: Backups, disaster recovery copies, older data that is still occasionally needed.
• Cost: Lower storage cost than Standard, but a per-GB retrieval fee.
• Minimum storage duration: 30 days — if you delete an object before 30 days, you still pay for 30 days.
• Minimum object size charge: 128 KB.
• Replication: Stored across 3+ Availability Zones.

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S3 One Zone-IA

Similar to Standard-IA but stored in a single Availability Zone instead of three or more.