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:
- Read how KV works.
- Create a KV namespace.
- Review the KV Runtime API.
- Learn about KV Limits.
R2
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:
- Read the Get started guide.
- Learn about R2 Limits.
- Review the R2 Workers API.
R2 and KV comparison
| Feature | KV | R2 (beta) |
|---|---|---|
| Maximum size per value | 25 MiB | 5 TB |
| Consistency model | Eventual | Strong |
| Cached | Always | Possible when using Cache API in a Worker |
| S3-compatible API | No | Yes |
| TTL expiration | Object-level | Not currently available |
| Maximum operations per second | Unlimited | < 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:
- Read the introductory blog post.
- Get started with Durable Objects.
- Review the Durable Objects Runtime API.
- Learn about Durable Objects Limits.