whichdb
vs

Amazon DynamoDB vs Azure Cosmos DB

Amazon DynamoDB: AWS's serverless key-value and document store with single-digit-millisecond reads at any scale. Azure Cosmos DB: Microsoft's globally distributed, multi-API NoSQL and vector database with SLA-backed latency.

key differences

  • Amazon DynamoDB is primarily a key-value database; Azure Cosmos DB is document.
  • Only Amazon DynamoDB has time travel, streaming ingest.
  • Only Azure Cosmos DB has full-text search, vector search, geospatial, stored procedures, columnar storage.

choose amazon-dynamodb for

  • +Serverless application backends on Lambda
  • +User profiles, sessions and shopping carts
  • +High-traffic e-commerce and gaming state
  • +IoT device state and metadata

best at · OLTP, Sessions, Cache

choose azure-cosmos-db for

  • +Globally distributed user and session data
  • +IoT telemetry and device state
  • +Chat history and memory for AI agents
  • +Retail carts, catalogs and personalization

best at · OLTP, IoT, Sessions

Amazon DynamoDBAWS's serverless key-value and document store with single-digit-millisecond reads at any scale.
Azure Cosmos DBMicrosoft's globally distributed, multi-API NoSQL and vector database with SLA-backed latency.
overview
Primary model
Key-Value
Document
Also supports
Document
Key-Value, Graph, Wide-Column, Vector, Search Engine
Type
Managed service
Managed service
Status
Active
Active
Developer
Amazon Web Services
Microsoft
First release
2012
2017
Latest version
–
–
License
ProprietaryProprietary (AWS service)
ProprietaryProprietary Azure service
Free tier
✓
✓
popularity
WhichDB Score
63.3
45.3
Rank
#14
#39
GitHub stars
–
–
Stack Overflow questions
14.3K
7.8K
scale & guarantees
Comfortable data size
Massive (Multi-PB)
Massive (Multi-PB)
Horizontal scaling
Native
Native
Multi-region
Active active
Active active
ACID
Limited
Limited
Consistency
Strong, Eventual
Tunable, Strong, Causal, Eventual
Schema
Schemaless
Schemaless
Architecture
Distributed, Serverless
Distributed, Multi primary, Serverless
deployment
Self-hosted
—
—
Vendor-managed cloud
✓
✓
Serverless
✓
✓
Embedded
—
—
Edge
—
—
Clouds
AWS
Azure
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
DynamoDB API, PartiQL
Cosmos DB NoSQL (SQL dialect), MongoDB Query API, CQL, Gremlin
Client languages
Java, Python, JavaScript, Go, C#, .NET, Rust, Ruby
C#, Java, JavaScript, Python, Go, Rust
Best for
OLTP, Sessions, Cache, Metadata
OLTP, IoT, Sessions, Vector search
Add more to this comparisonNot sure either fits? Try smart match

Amazon DynamoDB vs Azure Cosmos DB: FAQ

What is the difference between Amazon DynamoDB and Azure Cosmos DB?

Amazon DynamoDB: AWS's serverless key-value and document store with single-digit-millisecond reads at any scale. Azure Cosmos DB: Microsoft's globally distributed, multi-API NoSQL and vector database with SLA-backed latency. Amazon DynamoDB is primarily a key-value database; Azure Cosmos DB is document. Only Amazon DynamoDB has time travel, streaming ingest. Only Azure Cosmos DB has full-text search, vector search, geospatial, stored procedures, columnar storage.

When should I choose Amazon DynamoDB over Azure Cosmos DB?

Choose Amazon DynamoDB for serverless application backends on Lambda; user profiles, sessions and shopping carts; and high-traffic e-commerce and gaming state. Choose Azure Cosmos DB for globally distributed user and session data; IoT telemetry and device state; and chat history and memory for AI agents.

Is Amazon DynamoDB or Azure Cosmos DB more popular?

Amazon DynamoDB ranks #14 on the WhichDB Score (63.3/100) and Azure Cosmos DB ranks #39 (45.3/100). Popularity is not fit: check the requirements that matter for your project.

Are Amazon DynamoDB and Azure Cosmos DB open source?

No. Amazon DynamoDB is proprietary, closed-source software. No. Azure Cosmos DB is proprietary, closed-source software.