Object storage pricing glossary

Transfer, access and request meters

Egress: Data transferred out of a storage provider to the internet or another destination. It is a network-transfer meter, separate from any fee for reading data from a cold class. Source: Cloudflare developer docs: R2 pricing; retrieved 2026-07-26.

Retrieval: The processing or data-access charge for reading an object from an infrequent or archive class. It can apply in addition to request charges and egress, and some archive classes require a restore step before data can be read. Sources: Cloudflare developer docs: R2 pricing and AWS documentation: Storage class intro; retrieved 2026-07-26.

Class A operations: A vendor-defined bucket of API requests that usually create, list or mutate state. Cloudflare R2 puts operations such as PutObject, CopyObject and ListObjects in Class A, but the exact membership must come from each vendor. Source: Cloudflare developer docs: R2 pricing; retrieved 2026-07-26.

Class B operations: A vendor-defined bucket of API requests that usually read existing state. Cloudflare R2 includes GetObject and HeadObject in Class B, so a restore can generate Class B requests even when egress itself is free. Source: Cloudflare developer docs: R2 pricing; retrieved 2026-07-26.

Storage minimums and early deletion

Minimum storage duration: The shortest period for which an object is billed in a storage class. Reading an object does not end that period; deleting, replacing, moving or transitioning it early may create a charge for the remaining time. Source: Google Cloud: Storage pricing; retrieved 2026-07-26.

Early deletion: The charge for ending or changing storage before the class's minimum duration has elapsed. It is triggered by actions such as deletion, overwrite, move or transition, not by a read-only restore that leaves the source object unchanged. Sources: Google Cloud: Storage pricing and Microsoft Learn: Archive rehydrate overview; retrieved 2026-07-26.

Minimum billable capacity is the account-level storage floor charged when actual storage is lower. A minimum billable object size is a separate floor applied to each object. Neither is the same as the minimum time an object remains billable. Check the exact offer before assigning a numerical limit.

Object protection and retention

Object lock: A retention control that can prevent a specified object version from being deleted or overwritten for a fixed period or under a legal hold. Its exact protection depends on versioning, retention mode and permissions. Source: AWS documentation: Object lock; retrieved 2026-07-26.

Immutability: The property that protected data cannot be changed or deleted during the applicable retention rule. It is a behavior to verify, not a synonym for ordinary versioning or a marketing label. Source: AWS documentation: Object lock; retrieved 2026-07-26.

WORM: Write once, read many. A WORM control allows data to be written and read while preventing the protected version from being overwritten or deleted under its retention rule. Source: AWS documentation: Object lock; retrieved 2026-07-26.

Access classes and units

Storage class: A per-object tier that changes pricing, access behavior, minimum duration and retrieval treatment. The same provider can therefore have several offers that are not interchangeable for a backup workload. Source: Google Cloud: Storage classes; retrieved 2026-07-26.

Rehydration: The process of making archived data readable in an online tier, either by copying it or changing its tier where the provider permits. It can have a priority, delay, read-request charge and retrieval charge separate from later egress. Source: Microsoft Learn: Archive rehydrate overview; retrieved 2026-07-26.

GB and GiB use different byte counts. Preserve the provider’s published unit and name any conversion before comparing capacity or rates. Source: NIST: Binary; retrieved 2026-07-26.