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Amazon ElastiCache vs Amazon MemoryDB

Amazon ElastiCache: AWS's managed Valkey, Redis OSS and Memcached service, provisioned or serverless. Amazon MemoryDB: A durable, Valkey/Redis-compatible in-memory database on AWS backed by a multi-AZ transaction log.

key differences

  • Amazon ElastiCache is built for larger datasets (≤ 1 PB) than Amazon MemoryDB (≤ 10 TB).
  • Only Amazon ElastiCache has secondary indexes, full-text search, json.
  • Amazon ElastiCache has a serverless option; Amazon MemoryDB does not.

choose amazon-elasticache for

  • +Database query caching for RDS and DynamoDB
  • +Session storage for web apps on AWS
  • +Leaderboards and real-time counters
  • +Semantic caching for generative AI apps

best at · Cache, Sessions, Pub/Sub

choose amazon-memorydb for

  • +Durable session and shopping-cart state
  • +Primary database for microservices using Redis data structures
  • +Real-time leaderboards that must not lose updates
  • +Vector search close to application data

best at · Sessions, Cache, OLTP

Amazon ElastiCacheAWS's managed Valkey, Redis OSS and Memcached service, provisioned or serverless.
Amazon MemoryDBA durable, Valkey/Redis-compatible in-memory database on AWS backed by a multi-AZ transaction log.
overview
Primary model
Key-Value
Key-Value
Also supports
Vector, Search Engine
Vector
Type
Managed service
Managed service
Status
Active
Active
Developer
Amazon Web Services
Amazon Web Services
First release
2011
2021
Latest version
Valkey 9.1 engine (Jun 23, 2026)
–
License
ProprietaryAWS service terms
ProprietaryAWS service terms
Free tier
✓
✓
popularity
WhichDB Score
29.1
2.5
Rank
#89
#473
GitHub stars
–
–
Stack Overflow questions
916
25
scale & guarantees
Comfortable data size
Large (≤ 1 PB)
Medium (≤ 10 TB)
Horizontal scaling
Native
Native
Multi-region
Read replicas
Active active
ACID
Limited
Limited
Consistency
Eventual
Strong, Eventual
Schema
Schemaless
Schemaless
Architecture
In memory, Primary replica, Distributed, Serverless
In memory, Distributed, Primary replica
deployment
Self-hosted
—
—
Vendor-managed cloud
✓
✓
Serverless
✓
—
Embedded
—
—
Edge
—
—
Clouds
AWS
AWS
capabilities
Transactions
✓
✓
Joins
—
—
Secondary indexes
✓
—
Full-text search
✓
—
Vector search
✓
✓
Geospatial
✓
✓
JSON
✓
—
Change data capture
—
—
Triggers
—
—
Stored procedures
✓
✓
Materialized views
—
—
TTL / expiry
✓
✓
Pub/Sub
✓
✓
Columnar storage
—
—
In-memory
✓
✓
Durable persistence
✓
✓
Compression
—
—
Encryption at rest
✓
✓
Role-based access
✓
✓
Time travel
—
—
Branching
—
—
Online schema changes
—
—
Streaming ingest
✓
✓
Offline sync
—
—
Runs in WebAssembly
—
—
interfaces
Query languages
Redis commands (RESP), Memcached protocol, Lua
Redis commands (RESP), Lua
Client languages
Python, Java, JavaScript, Go, C#, Rust, Ruby, PHP
Python, Java, JavaScript, Go, C#, Rust, Ruby, PHP
Best for
Cache, Sessions, Pub/Sub, Queue
Sessions, Cache, OLTP, Vector search
Add more to this comparisonNot sure either fits? Try smart match

Amazon ElastiCache vs Amazon MemoryDB: FAQ

What is the difference between Amazon ElastiCache and Amazon MemoryDB?

Amazon ElastiCache: AWS's managed Valkey, Redis OSS and Memcached service, provisioned or serverless. Amazon MemoryDB: A durable, Valkey/Redis-compatible in-memory database on AWS backed by a multi-AZ transaction log. Amazon ElastiCache is built for larger datasets (≤ 1 PB) than Amazon MemoryDB (≤ 10 TB). Only Amazon ElastiCache has secondary indexes, full-text search, json. Amazon ElastiCache has a serverless option; Amazon MemoryDB does not.

When should I choose Amazon ElastiCache over Amazon MemoryDB?

Choose Amazon ElastiCache for database query caching for RDS and DynamoDB; session storage for web apps on AWS; and leaderboards and real-time counters. Choose Amazon MemoryDB for durable session and shopping-cart state; primary database for microservices using Redis data structures; and real-time leaderboards that must not lose updates.

Is Amazon ElastiCache or Amazon MemoryDB more popular?

Amazon ElastiCache ranks #89 on the WhichDB Score (29.1/100) and Amazon MemoryDB ranks #473 (2.5/100). Popularity is not fit: check the requirements that matter for your project.

Are Amazon ElastiCache and Amazon MemoryDB open source?

No. Amazon ElastiCache is proprietary, closed-source software. License: AWS service terms. No. Amazon MemoryDB is proprietary, closed-source software. License: AWS service terms.