KeyDB review covering multi-threading, performance benchmarks, Redis compatibility, and how it compares to Redis, Valkey and Dragonfly.
KeyDB is an open-source, multi-threaded fork of Redis originally built by John Sully and Ben Schermel at EQ Alpha Technology and acquired by Snap Inc. in May 2022. Snap had already been running KeyDB across much of its own caching infrastructure before acquiring the team, and as part of the deal, previously commercial 'KeyDB Pro' features were merged into the open-source codebase under a BSD-3 license, making the full feature set free to use.
The project's defining trait is multi-threading: KeyDB runs Redis's core event loop concurrently across multiple CPU threads rather than a single thread, using multi-version concurrency control (MVCC) to serve consistent snapshots without blocking. This lets a single KeyDB node exceed one million operations per second and significantly outperform standard single-threaded Redis on multi-core hardware, while remaining fully protocol-compatible so it can act as a drop-in replacement.
Beyond raw throughput, KeyDB adds capabilities not found in standard open-source Redis, including Active Replication for multi-master, active-active setups without needing separate Sentinel nodes, Subkey Expires for setting TTLs on individual members within a hash or other complex structure, and ModJS, a V8-based JavaScript scripting engine offered as a faster alternative to Lua. It also supports cluster-mode sharding with automatic failover for horizontal scaling.
KeyDB supports the same core Redis data structures (strings, hashes, lists, sets, sorted sets, bitmaps, HyperLogLogs, geospatial indexes, streams) and offers comparable persistence options, including periodic snapshotting and append-only-file logging, giving teams configurable durability without sacrificing Redis compatibility.
KeyDB is entirely free and open-source, licensed under BSD-3 with no separate commercial tier, subscription, or paid license required to access any feature, including capabilities that were previously gated behind a commercial 'KeyDB Pro' offering before Snap's acquisition folded them into the open codebase.
Because there is no managed cloud product offered directly by the KeyDB project, organizations run it on their own infrastructure (self-hosted, containerized, or on Kubernetes) and costs are limited to compute and operational overhead rather than any licensing fee.
Yes, KeyDB is fully open-source under a BSD-3 license with no paid tier or licensing fee required for any feature.
KeyDB was created by John Sully and Ben Schermel at EQ Alpha Technology and was acquired by Snap Inc. in May 2022, which now maintains the project.
KeyDB is multi-threaded, running the Redis event loop across multiple CPU cores concurrently, whereas standard Redis is single-threaded, giving KeyDB higher throughput on multi-core hardware while remaining protocol-compatible.
Yes, KeyDB maintains full Redis protocol compatibility, including support for modules and Lua scripts, making it a drop-in replacement.
Active Replication is KeyDB's multi-master, active-active replication feature that lets multiple nodes accept writes and replicate to each other without requiring separate Sentinel nodes.
The main alternatives are Redis itself, Valkey (the Linux Foundation-backed community fork of Redis), and Dragonfly, another multi-threaded Redis-compatible in-memory database.