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Storage options guide

The Cloudflare Workers platform provides multiple storage options. This guide will inform you on which storage option is appropriate based on your project’s use case.

​​ KV

Workers KV is an eventually consistent key-value data store that caches on the edge.

It is ideal for projects that require:

  • High volumes of reads and/or repeated reads to the same keys.
  • Per-object time-to-live (TTL).
  • Asset storage for websites.

To get started with KV:

​​ R2 (beta)

R2 is S3-compatible blob storage that allows developers to store large amounts of unstructured data without egress fees associated with typical cloud storage services.

It is ideal for projects that require:

  • Storage for files which are infrequently accessed.
  • Large object storage.
  • Strong consistency per object.

To get started with R2:

​​ R2 and KV comparison

FeatureKVR2 (beta)
Maximum size per value25 MiB5 TB
Consistency modelEventualStrong
CachedAlwaysPossible when using Cache API in a Worker
S3-compatible APINoYes
TTL expirationObject-levelNot currently available
Maximum operations per secondUnlimited< 1,000/bucket

​​ Durable Objects

Durable Objects provide low-latency coordination and consistent storage for the Workers platform through global uniqueness and a transactional storage API.

  • Global Uniqueness guarantees that there will be a single instance of a Durable Object class with a given ID running at once, across the world. Requests for a Durable Object ID are routed by the Workers runtime to the Cloudflare data center that owns the Durable Object.

  • The transactional storage API provides strongly consistent key-value storage to the Durable Object. Each Object can only read and modify keys associated with that Object. Execution of a Durable Object is single-threaded, but multiple request events may still be processed out-of-order from how they arrived at the Object.

It is ideal for projects that require:

  • Real-time collaboration (such as a chat application or a game server).
  • Consistent storage.
  • Data locality.

To get started with Durable Objects: