What is the top free pick among key-value stores and caches?

Redis leads the Stack Gems list for key-value stores and caches. Verdict: The default choice for caching and session storage.

How many key-value stores and caches does Stack Gems review?

5: 4 free or open source, 1 hosted with a real free tier. Each review has a verdict and an honest Catch; no tool pays for its spot.

Which key-value stores and caches can I self-host for free?

Redis, Valkey, etcd and Garnet.

Which key-value stores and caches have the most GitHub stars?

Redis (77k), etcd (52.4k), Valkey (27.5k), per GitHub on 2026-10-19. Stars measure attention, not fit; read the Catch.

What is the catch with Redis?

License: not MIT. Since Redis 8 the server is tri-licensed RSALv2 / SSPLv1 / AGPLv3 at your choice — AGPLv3 is the only OSI option and carries network copyleft; 7.4–7.x was RSALv2/SSPLv1 only.

Best of · Databases

Best key-value stores and caches (2026)

Stack Gems reviews 5 key-value stores and caches: 4 free or open source, 1 hosted with a real free tier. These are the top 5, each with its verdict and the Catch we would want to know before installing it.

Order: free and open source first, then hosted products with a real free tier, then paid-led; catalog order inside each group, with quiet or archived repos last. Not a score, and no tool pays for its place.

5 reviewed · 5 shown in full

1.RedisThe in-memory data store everyone uses
Free / OSS · RSALv2/SSPLv1/AGPLv3 · 77k GitHub stars
VerdictThe default choice for caching and session storage.
CatchLicense: not MIT. Since Redis 8 the server is tri-licensed RSALv2 / SSPLv1 / AGPLv3 at your choice — AGPLv3 is the only OSI option and carries network copyleft; 7.4–7.x was RSALv2/SSPLv1 only. If you need BSD-3 Redis-protocol, look at Valkey. Memory-bound storage is expensive at scale. Persistence options have tradeoffs. Clustering adds complexity.
2.ValkeyBSD-3-Clause forever-OSS Redis-protocol KV after the license fork
Free / OSS · BSD-3-Clause · 27.5k GitHub stars
VerdictBSD-3 forever-OSS Redis protocol. Fork lane, not a speed upgrade.
CatchForever-OSS Redis-protocol fork lane, not Redis but faster. Valkey is the license/governance fork, not a performance twin. Don’t assume a managed free tier.
3.etcdApache-2.0 Raft key-value store underneath Kubernetes
Free / OSS · Apache-2.0 · 52.4k GitHub stars
VerdictThe proven store for cluster coordination and config — keep it small and run it as a proper cluster.
CatchIt is built for small, strongly consistent data, not as a message queue, cache or bulk store: values and total database size are meant to stay small, and every write goes through consensus. Production means running a cluster of three or five nodes on fast disks and handling backups, compaction and defragmentation yourself. For an app database, use Postgres; reach for etcd when you need coordination.
4.GarnetMIT Redis-protocol cache-store from Microsoft Research
Free / OSS · OSS/MIT · 12.1k GitHub stars
VerdictA serious MIT alternative to Redis when throughput per box matters — test your command set first.
CatchRESP compatibility is not full Redis: check your exact commands and modules against Garnet's API docs before swapping it in. Custom extensions are written in C#/.NET, so this fits best in a .NET team. The headline latency numbers come from the project's own benchmarks on Azure VMs. The managed Azure Cosmos DB Garnet Cache is a separate paid service; the OSS server is free.
5.UpstashServerless Redis and Kafka
Free tier · Freemium
VerdictRedis that fits the serverless model perfectly.
CatchHTTP adds latency compared to native Redis protocol. High-throughput workloads get expensive. Some Redis features are not available.

FAQ

What is the top free pick among key-value stores and caches?: Redis leads the Stack Gems list for key-value stores and caches. Verdict: The default choice for caching and session storage.
How many key-value stores and caches does Stack Gems review?: 5: 4 free or open source, 1 hosted with a real free tier. Each review has a verdict and an honest Catch; no tool pays for its spot.
Which key-value stores and caches can I self-host for free?: Redis, Valkey, etcd and Garnet.
Which key-value stores and caches have the most GitHub stars?: Redis (77k), etcd (52.4k), Valkey (27.5k), per GitHub on 2026-10-19. Stars measure attention, not fit; read the Catch.
What is the catch with Redis?: License: not MIT. Since Redis 8 the server is tri-licensed RSALv2 / SSPLv1 / AGPLv3 at your choice — AGPLv3 is the only OSI option and carries network copyleft; 7.4–7.x was RSALv2/SSPLv1 only.

Best key-value stores and caches (2026)

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