Redis vs Memcached
Redis is an in-memory data store with rich data structures, persistence, pub/sub, Lua scripting, and vector search via RediSearch. Memcached is a simpler, multi-threaded cache focused purely on key-value speed. Redis is more versatile; Memcached is leaner for pure caching workloads.
Redis Vector
Sub-millisecond vector search in memory
CRedis Source Available Licensetraditional
Key Features
- Sub-millisecond latency
- In-memory vector index
- HNSW & FLAT algorithms
- Hybrid vector + tag filtering
- Redis Stack modules
- Redis Enterprise Cloud
Pricing
Open SourceFree
Cloud (Free)$0
Cloud (Essentials)From $5/mo
EnterpriseCustom
Use Cases
Real-time recommendationsChatbot session memoryLow-latency semantic searchCaching + similarity
M
Memcached
High-performance, multi-threaded, in-memory key-value cache
CBSDopen-source
Key Features
- Multi-threaded architecture
- Simple key-value storage
- LRU eviction
- UDP and TCP support
- Consistent hashing
- Slab memory allocator
Pricing
Self-hostedFree
AWS ElastiCacheFrom $0.017/hr
Use Cases
Session cachingPage cachingAPI response cachingDatabase query caching
Verdict
Redis for versatility, persistence, and AI/vector capabilities. Memcached for simple, high-throughput caching where you don't need advanced features.
Choose Redis Vector if you need:
- ✓Sub-millisecond latency
- ✓In-memory vector index
- ✓HNSW & FLAT algorithms
Choose Memcached if you need:
- ✓Self-hosted deployment flexibility
- ✓No vendor lock-in or usage limits
- ✓Multi-threaded architecture
- ✓Simple key-value storage
- ✓LRU eviction