S3 One Zone-IA is designed for infrequently accessed data that is easily re-creatable or has secondary copies elsewhere, offering 20% cost savings over Standard-IA by storing data in a single Availability Zone.
S3 One Zone-Infrequent Access (One Zone-IA) is a storage class for data accessed less frequently but needing rapid access when required. Unlike other S3 classes that store data across a minimum of three Availability Zones (AZs), One Zone-IA stores data in a single AZ, making it 20% less expensive than S3 Standard-IA [citation:1][citation:2]. However, this cost savings comes with the trade-off that data will be lost in the event of an AZ destruction, as it is not resilient to such failures [citation:2][citation:3].
Store secondary backup copies of on-premises data where the primary backup exists elsewhere [citation:1][citation:3][citation:10]
Ideal for backups that are already replicated to another AWS Region for compliance or disaster recovery purposes [citation:1][citation:10]
Example: Nearmap uses One Zone-IA for a large portion of their stored aerial imagery data, supporting their continued growth [citation:10]
Store data that can be regenerated from original sources, such as thumbnail images created from original photos [citation:3][citation:7][citation:9]
Example: An application processing user-uploaded images into thumbnails can store those thumbnails in One Zone-IA since they can be recreated from the original images if lost [citation:7]
Example: Keepsafe Photo Vault uses One Zone-IA for backup data, as copies of the data exist on mobile or desktop clients [citation:10]
Use as a cost-effective target for S3 Cross-Region Replication from another AWS Region [citation:2][citation:3]
Data replicated to another region already has its primary copy, making single-AZ storage acceptable for the secondary copy [citation:1][citation:10]
AZ Failure Risk: Data stored in One Zone-IA will be permanently lost in the event of an Availability Zone destruction [citation:2][citation:3][citation:7]
Not for Primary/Only Copies: Should not be used for data that cannot be recreated or for which no other copy exists [citation:7]
Minimum Storage Duration: 30-day minimum retention period applies [citation:3][citation:7][citation:8]
Minimum Object Size: 128 KB minimum object size [citation:3][citation:8]
Availability SLA: Designed for 99.5% availability, lower than Standard-IA's 99.9% [citation:2][citation:7]
One Zone-IA is not suitable for primary data storage, critical application data, or the only copy of important information. For example, application logs that are stored only in S3 and not backed up elsewhere should use Standard-IA instead of One Zone-IA to ensure availability [citation:7]. The critical factor is whether data loss in a single AZ would be acceptable—if the answer is no, choose Standard-IA or S3 Standard instead [citation:2].