S3 storage classes




S3 is one of the most commonly used services in AWS and is also handy when it comes to the storage of objects. In this blog, I will be highlighting my deeper understanding of the service.

S3 Overview

Amazon S3 allows the storage of objects or files in buckets .

Buckets must have a globally unique name and be defined at the region level .

  • No uppercase
  • No underscore
  • Must start with a lowercase letter or number
  • 3-63 characters long


Objects are files stored in the bucket, they have a key which is the full path. You can either add a file or a folder.

<my_bucket>/my_file.txt <my_bucket>/my_folder1/another_folder/my_file.txt

The object values ​​are the content of the body:

  • Max size is 5TB
  • If uploading more than 5GB, must use "multi-part upload"

 Note:  There are no directories within the buckets though the UI will make you think otherwise.

S3 Storage Classes

  1. Amazon S3 Standard
  2. Amazon S3 Standard-Infrequent Access (IA)
  3. Amazon S3 One Zone-Infrequent Access
  4. Amazon S3 Glacier
  5. Amazon S3 Intelligent Tiering

Objects can be moved between classes manually or using S3 lifecycle configurations.


S3 Durability and Availability


High durability (99.999999999%,) 11 9's of objects across multiple AZ. In essence, if you store 10 million objects with Amazon S3, the expected loss to incur on average is a single object once every 10,000 years.


This is the ability to measure how readily available the service is. S3 standard has 99.99% availability

Looking at each storage class based on their availability.

S3 Standard – General Purpose

  • 99.99% Availability
  • Used for frequently accessed data
  • Low latency and high throughput
  • Use Cases: Big Data analytics, mobile and gaming applications, content distribution

S3 Storage Classes – Infrequent Access

Used in situations where data is less frequently accessed, but requires rapid access when needed. It offers a Lower cost than S3 Standard

Amazon S3 Standard-Infrequent Access (S3 Standard-IA)

    • 99.9% Availability
    • Use cases: Disaster Recovery, backups

Amazon S3 One Zone-Infrequent Access (S3 One Zone-IA)

    • 99.5% Availability
    • High durability (99.999999999%) in a single AZ; data is lost when AZ is destroyed
    • Use Cases: Storing secondary backup copies of on-premise data, or data you can recreate

Amazon S3 Glacier Storage Classes

  • Low-cost object storage meant for archiving / backup
  • Pricing: Price for storage + object retrieval cost

• Amazon S3 Glacier Instant Retrieval

      • Millisecond retrieval is great for data accessed once a quarter
      • Minimum storage duration of 90 days

• Amazon S3 Glacier Flexible Retrieval (formerly Amazon S3 Glacier):

      • Expedited (1 to 5 minutes), Standard (3 to 5 hours), Bulk (5 to 12 hours) – free
      • Minimum storage duration of 90 days

• Amazon S3 Glacier Deep Archive – for long-term storage:

      • Standard (12 hours), Bulk (48 hours)
      • Minimum storage duration of 180 days

S3 Intelligent-Tiering

  • Small monthly monitoring and auto-tiering fee
  • Moves objects automatically between Access Tiers based on usage
  • There are no retrieval charges in S3 Intelligent-Tiering