Redis vs Memcached: Which MCP should you use?
Redis
In-memory data structure store
Memcached
Distributed memory caching system
TL;DR
Redis is a rich data-structure server (strings, hashes, streams, pub/sub, scripts, persistence). Memcached is a minimalist multi-threaded in-memory key/value cache. Pick Memcached if you literally only need a cache; Redis does that plus everything else.
Pick Redis
Pick Redis when you want queues, pub/sub, persistence, rate limits, or sorted sets.
Pick Memcached
Pick Memcached when you need pure cache, no durability, with simple multi-threaded performance.
Feature-by-feature comparison
| Feature | 🔴Redis | 💾Memcached | Winner |
|---|---|---|---|
| Data structures | Hashes, lists, sets, streams, JSON | Strings only | A |
| Persistence | RDB + AOF | None (pure cache) | A |
| Threading | Mostly single-threaded (I/O MT) | Multi-threaded | B |
| Pub/Sub + streams | Yes | No | A |
| Cluster support | Redis Cluster built-in | Client-side sharding | A |
| Memory efficiency (pure KV) | Good | Excellent (slab allocator) | B |
| Scripting | Lua + Functions | None | A |
| License change impact | RSALv2/SSPLv1 (then v8 moved to AGPL-3) | BSD | B |
Data structures
ARedis
Hashes, lists, sets, streams, JSON
Memcached
Strings only
Persistence
ARedis
RDB + AOF
Memcached
None (pure cache)
Threading
BRedis
Mostly single-threaded (I/O MT)
Memcached
Multi-threaded
Pub/Sub + streams
ARedis
Yes
Memcached
No
Cluster support
ARedis
Redis Cluster built-in
Memcached
Client-side sharding
Memory efficiency (pure KV)
BRedis
Good
Memcached
Excellent (slab allocator)
Scripting
ARedis
Lua + Functions
Memcached
None
License change impact
BRedis
RSALv2/SSPLv1 (then v8 moved to AGPL-3)
Memcached
BSD
Best for
Redis
- Data structures: Hashes, lists, sets, streams, JSON
- Persistence: RDB + AOF
- Pub/Sub + streams: Yes
- Cluster support: Redis Cluster built-in
- Scripting: Lua + Functions
Best for
Memcached
- Threading: Multi-threaded
- Memory efficiency (pure KV): Excellent (slab allocator)
- License change impact: BSD
Migration path
Moving from Memcached to Redis is usually a drop-in swap at the client layer — both speak simple GET/SET. Rewrite any binary protocol code, and take advantage of Redis hashes to replace compound keys. The other direction is rare; if you must, strip all non-KV code paths and accept no persistence.
Frequently asked questions
What is the main difference between Redis and Memcached?
Redis is a rich data-structure server (strings, hashes, streams, pub/sub, scripts, persistence). Memcached is a minimalist multi-threaded in-memory key/value cache. Pick Memcached if you literally only need a cache; Redis does that plus everything else. In short: Redis — In-memory data structure store. Memcached — Distributed memory caching system.
When should I pick Redis over Memcached?
Pick Redis when you want queues, pub/sub, persistence, rate limits, or sorted sets.
When should I pick Memcached over Redis?
Pick Memcached when you need pure cache, no durability, with simple multi-threaded performance.
Can I migrate from one to the other?
Moving from Memcached to Redis is usually a drop-in swap at the client layer — both speak simple GET/SET. Rewrite any binary protocol code, and take advantage of Redis hashes to replace compound keys. The other direction is rare; if you must, strip all non-KV code paths and accept no persistence.
Do Redis and Memcached both work with MCP-compatible AI agents?
Redis has an MCP server installable via MCPizy (mcpizy install redis). Memcached is not yet in the MCPizy directory — check its vendor's own docs for an MCP server.
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Install Redis with MCPizy
Memcached isn't in the MCPizy directory yet — install Redis and compare it against Memcached manually.