Transition
- What it is
- The lifecycle policy action that moves an object to a cheaper Amazon S3 storage class after it reaches a given age. The object stays; only where it lives changes.
- The usual ladder
- S3 Standard → S3 Standard-IA (30+ days) → S3 Glacier Flexible Retrieval (90+ days) → S3 Glacier Deep Archive (180+ days).
- Rules that bite
- Minimum storage durations still apply — transitioning early still bills the minimum for the class you left.
- Objects smaller than 128 KB are not worth transitioning; per-object transition requests can cost more than the storage saved.
- Transitions only move down the cost ladder automatically; going back up means a restore or a copy.
- Related but different
- Expiration — deletes the object instead of moving it.
- S3 Intelligent-Tiering — S3 decides from observed access, with no rules to write.