Redis vs Memcached

In-memory data stores compared: Redis with its rich data structures vs Memcached for pure caching performance.

Redis

In-memory data structure store used as database, cache, message broker, and streaming engine.

Free (RSAL license), Redis Cloud from $0/mo

Best For

Applications needing caching plus data structures, pub/sub, sessions, and real-time features

Pros

Rich data structures (lists, sets, hashes)
Persistence options (RDB + AOF)
Pub/Sub and Streams for messaging
Lua scripting support
Redis Cluster for horizontal scaling

Cons

Single-threaded for commands
Higher memory overhead per key
More complex to configure
Licensing changes (Redis Source Available)

Memcached

High-performance, distributed memory object caching system for simple key-value caching.

Free, open-source (BSD)

Best For

Pure caching scenarios where simplicity and raw throughput are top priorities

Pros

Multi-threaded (uses all CPU cores)
Lower memory overhead per key
Simpler to operate
Predictable performance
True open-source (BSD license)

Cons

Only simple key-value storage
No persistence (cache only)
No built-in clustering
Limited data type support

Feature Comparison

Feature	Redis	Memcached
Data Types	Strings, Lists, Sets, Hashes, Sorted Sets, Streams	Strings only
Persistence	RDB snapshots + AOF	None (volatile only)
Threading	Single-threaded (I/O threads in 6.0+)	Multi-threaded
Max Value Size	512MB	1MB (default)
Pub/Sub	Yes	No
Clustering	Redis Cluster (built-in)	Client-side sharding
Scripting	Lua scripts	None
Eviction Policies	8 policies	LRU only

Community Vote

Redis (50%)Memcached (50%)

0 total votes

Our Verdict

Redis is the clear winner for most modern applications, offering caching plus rich data structures, persistence, and messaging. Memcached still has a place for pure caching workloads where multi-threaded performance and simplicity matter. Unless you specifically need only simple key-value caching, Redis is the better default choice.