This page explains the concept ofstorage class and the differences betweenstorage classes.

• To learn how to change the storage class of an object, seeChanging object storage classes.

• To learn how to change a bucket's default storage class, seeChanging the default storage class.

Key concepts

• Astorage class is a piece ofmetadata that is used by every object.

• The storage class set for an object affects the object's availabilityandpricing model.

• When youcreate a bucket, you can specify adefault storage classfor the bucket. When you add objects to the bucket, they inherit this storageclass 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 anyof the objects that already exist in the bucket.

• You can change the storage class of an existing object either byrewriting the object or by usingObject Lifecycle Management.

• You can enable theAutoclass feature on a bucket to letCloud Storage manage storage class transitions for youautomatically.

Available storage classes

The following table summarizes the primary storage classes offered byCloud Storage. Seeclass descriptions for a completediscussion.

Storage Class	Name for APIs and CLIs	Minimum storage duration	Retrieval fees	Typical monthly availability1
Standard storage	STANDARD	None	None	>99.99% in multi-regions and dual-regions 99.99% in regions
Nearline storage	NEARLINE	30 days	Yes	99.95% in multi-regions and dual-regions 99.9% in regions
Coldline storage	COLDLINE	90 days	Yes	99.95% in multi-regions and dual-regions 99.9% in regions
Archive storage	ARCHIVE	365 days	Yes	99.95% in multi-regions and dual-regions 99.9% in regions

¹See theclass descriptions for theavailabilitySLA for each storage class.

Class descriptions

The following features apply to all storage classes:

• Unlimited storage with unlimited access.
• No minimum object size.
• Worldwide accessibility and worldwidestorage locations.
• Low latency with no offline data retrieval.
• High durability (99.999999999% annual durability).
• Redundancy across regions when data is stored in a multi-region ordual-region.
• 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.

When used in a region, Standard storage is appropriate for storing data inthe same location asGoogle Kubernetes Engine clusters orCompute Engine instances that use the data. Co-locating your resourcesmaximizes the performance for data-intensive computations and can reducenetwork charges.

When used in a dual-region, you still get optimized performance when accessingGoogle Cloud products that are located in one of the associated regions, butyou also get the improved availability that comes from storing data ingeographically separate locations.

When used in a multi-region, Standard storage is appropriate for storing datathat is accessed around the world, such as serving website content, streamingvideos, executing interactive workloads, or serving data supporting mobile andgaming applications.

Availability

The availability of Standard storage data is:

Location Type	Availability SLA1	Typical monthly availability
multi-region	99.95%	>99.99%
dual-region	99.95%	>99.99%
region	99.9%	99.99%

¹The availability SLA is the monthly uptime percentage backed bytheCloud Storage SLA. If Google fails to meet that uptime,customers are eligible to receive a credit as described in theCloud Storage SLA.

Nearline storage

Nearline storage is a low-cost, highly durable storage service for storinginfrequently accessed data. Nearline storage is a better choice thanStandard storage in scenarios where slightly lower availability, a 30-dayminimum storage duration, and costs for data access are acceptable trade-offsfor loweredat-rest storage costs.

Nearline storage is ideal for data you plan to read or modify on average onceper month or less. For example, if you want to continuously add files toCloud Storage and plan to access those files once a month foranalysis, Nearline storage is a great choice.

Nearline storage is also appropriate for data backup, long-tail multimediacontent, and data archiving. Note, however, that for data accessed lessfrequently than once a quarter, Coldline storage or Archive storage are morecost-effective, as they offer lower storage costs.

Availability

The availability of Nearline storage data is:

Location Type	Availability SLA1	Typical monthly availability
multi-region	99.9%	99.95%
dual-region	99.9%	99.95%
region	99.0%	99.9%

¹The availability SLA is the monthly uptime percentage backed bytheCloud Storage SLA. If Google fails to meet that uptime,customers are eligible to receive a credit as described in theCloud Storage SLA.

Coldline storage

Coldline storage is a very-low-cost, highly durable storage service forstoring infrequently accessed data. Coldline storage is a better choice thanStandard storage or Nearline storage in scenarios where slightly loweravailability, a 90-day minimum storage duration, and higher costs for dataaccess are acceptable trade-offs for loweredat-rest storage costs.

Coldline storage is ideal for data you plan to read or modify at most once aquarter. Note, however, that for data being kept entirely for backup orarchiving purposes, Archive storage is more cost-effective, as it offers thelowest storage costs.

Availability

The availability of Coldline storage data is:

Location Type	Availability SLA1	Typical monthly availability
multi-region	99.9%	99.95%
dual-region	99.9%	99.95%
region	99.0%	99.9%

¹The availability SLA is the monthly uptime percentage backed bytheCloud Storage SLA. If Google fails to meet that uptime,customers are eligible to receive a credit as described in theCloud Storage SLA.

Archive storage

Archive storage is the lowest-cost, highly durable storage service for dataarchiving, online backup, and disaster recovery. Unlike the "coldest" storageservices offered by other Cloud providers, your data is available withinmilliseconds, not hours or days.

Like Nearline storage and Coldline storage, Archive storage has a slightlylower availability than Standard storage. Archive storage also has highercosts for data access and operations, as well as a 365-day minimum storageduration. Archive storage is the best choice for data that you plan to accessless than once a year. For example:

• Cold data storage - Archived data, such as data stored for legalor regulatory reasons, can be stored at low cost as Archive storage, yetstill be available if you need it.

• Disaster recovery - In the event of a disaster recovery event, recoverytime is key. Cloud Storage provides low latency access to data stored asArchive storage.

Availability

The availability of Archive storage data is:

Location Type	Availability SLA1	Typical monthly availability
multi-region	99.9%	99.95%
dual-region	99.9%	99.95%
region	99.0%	99.9%

¹The availability SLA is the monthly uptime percentage backed bytheCloud Storage SLA. If Google fails to meet that uptime,customers are eligible to receive a credit as described in theCloud Storage SLA.

Additional classes

Cloud Storage supports several additional legacy storage classes;however, these legacy classes cannot be set using the Google Cloud console.Unless you already are using one of these legacy classes, you should useStandard storage instead.

• Multi-Regional storage: Equivalent to Standard storage, exceptMulti-Regional storage can only be used for objects stored inmulti-regions ordual-regions.

• Regional storage: Equivalent to Standard storage, exceptRegional storage can only be used for objects stored inregions.

• Durable Reduced Availability (DRA) storage: Similar to Standard storage except:

  • DRA has higher pricing for operations.
  • DRA has lower performance, particularly in terms ofavailability (DRA has a 99% availability SLA).

  You can move your data from DRA to other storage classes byperforming a storage transfer.

Note: Whenenabling Autoclass on your bucket, legacy storage classes areconsidered to be different from Standard storage. For example, objects inyour bucket other than soft-deleted objects transition to Standard storagewhen Autoclass is enabled, and this includes objects stored in legacy classes.

Pricing

Storage classes affect the pricing model of objects and the operations youperform. For information about how storage classes affect pricing, seeCloud Storage pricing.

What's next

• Create a Cloud Storage bucket.
• Compare storage costs for different storage classes.
• Upload an object to Cloud Storage.
• Change the storage class of an individual object.
• Learn about the Object Lifecycle Management feature.

Try it for yourself

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