This page explains the concept of storage class and the differences between storage classes.
To learn how to change the storage class of an object, see Changing object storage classes.
To learn how to change a bucket's default storage class, see Changing the default storage class.
Key concepts
A storage class is a piece of metadata that is used by every object.
The storage class set for an object affects the object's availability and pricing model.
When you create a bucket, you can specify a default storage class for the bucket. When you add objects to the bucket, they inherit this storage class unless explicitly set otherwise.
If you don't specify a default storage class when you create a bucket, that bucket's default storage class is set to Standard storage.
Changing the default storage class of a bucket does not affect any of the objects that already exist in the bucket.
You can change the storage class of an existing object either by rewriting the object or by using Object Lifecycle Management.
You can enable the Autoclass feature on a bucket to let Cloud Storage manage storage class transitions for you automatically.
Available storage classes
The following table summarizes the primary storage classes offered by Cloud Storage.
| Storage Class | Name for APIs and CLIs | Minimum storage duration | Retrieval fees | Typical monthly availability |
|---|---|---|---|---|
| Standard storage | STANDARD |
None | None | 99.99% |
| Nearline storage | NEARLINE |
30 days | Yes | 99.9% |
| Coldline storage | COLDLINE |
90 days | Yes | 99.9% |
| Archive storage | ARCHIVE |
365 days | Yes | 99.9% |
Class descriptions
The following features apply to all storage classes:
- Unlimited storage with unlimited access.
- No minimum object size.
- Low latency with no offline data retrieval.
- High durability (99.999999999% annual durability).
- A uniform experience with Cloud Storage features, security, tools, and APIs.
Standard storage
Standard storage is best for data that is frequently accessed ("hot" data), as well as data that is stored for only brief periods of time.
Standard storage is appropriate for storing data to be used in Google Kubernetes Engine clusters or Compute Engine instances.
Nearline storage
Nearline storage is a low-cost, highly durable storage service for storing infrequently accessed data. Nearline storage is a better choice than Standard storage in scenarios where slightly lower availability, a 30-day minimum storage duration, and costs for data access are acceptable trade-offs for lowered at-rest storage costs.
Nearline storage is ideal for data you plan to read or modify on average once per month or less. For example, if you want to continuously add files to Cloud Storage and plan to access those files once a month for analysis, Nearline storage is a great choice.
Nearline storage is also appropriate for data backup, long-tail multimedia content, and data archiving. Note, however, that for data accessed less frequently than once a quarter, Coldline storage or Archive storage are more cost-effective, as they offer lower storage costs.
Coldline storage
Coldline storage is a very-low-cost, highly durable storage service for storing infrequently accessed data. Coldline storage is a better choice than Standard storage or Nearline storage in scenarios where slightly lower availability, a 90-day minimum storage duration, and higher costs for data access are acceptable trade-offs for lowered at-rest storage costs.
Coldline storage is ideal for data you plan to read or modify at most once a quarter. Note, however, that for data being kept entirely for backup or archiving purposes, Archive storage is more cost-effective, as it offers the lowest storage costs.
Archive storage
Archive storage is the lowest-cost, highly durable storage service for data archiving, online backup, and disaster recovery. Unlike the "coldest" storage services offered by other Cloud providers, your data is available within milliseconds, not hours or days.
Like Nearline storage and Coldline storage, Archive storage has a slightly lower availability than Standard storage. Archive storage also has higher costs for data access and operations, as well as a 365-day minimum storage duration. Archive storage is the best choice for data that you plan to access less than once a year. For example:
Cold data storage - Archived data, such as data stored for legal or regulatory reasons, can be stored at low cost as Archive storage, yet still be available if you need it.
Disaster recovery - In the event of a disaster recovery event, recovery time is key. Cloud Storage provides low latency access to data stored as Archive storage.