Amazon RDS vs Microsoft Azure Cosmos DB comparison

Amazon Web Services (AWS) and Microsoft are both solutions in the Database as a Service (DBaaS) category. Amazon Web Services (AWS) is ranked #2 with an average rating of 8.4, while Microsoft is ranked #4 with an average rating of 8.3. Amazon Web Services (AWS) holds a 14.8% mindshare in DS, compared to Microsoft’s 4.1% mindshare. Additionally, 98% of Amazon Web Services (AWS) users are willing to recommend the solution, compared to 95% of Microsoft users who would recommend it.

Amazon RDS

Read 58 Amazon RDS reviews

3,594 Views
3,486 Comparison Views

98% willing to recommend

Microsoft Azure Cosmos DB

Read 109 Microsoft Azure Cosmos DB reviews

9,934 Views
1,291 Comparison Views

95% willing to recommend

Amazon RDS

Microsoft Azure Cosmos DB

Comparison Buyer's Guide

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Executive SummaryUpdated on Jan 25, 2026

Amazon RDS and Microsoft Azure Cosmos DB compete in the cloud-based database solutions category. Amazon RDS appears to have the upper hand in managing relational databases due to its full automation and support for multiple database types, while Cosmos DB excels in API versatility and integration with Azure services.

Features: Amazon RDS is adept at managing relational databases with full automation features, including robust backup and resilience in multi-availability zones. It supports diverse databases like MySQL and SQL Server and offers significant deployment agility. Microsoft Azure Cosmos DB offers multi-model and NoSQL capabilities, supports seamless integration with other Azure services, and provides global distribution, low-latency access, and auto-scaling, making it ideal for IoT and globally distributed applications.

Room for Improvement: Amazon RDS encounters challenges with complex migrations, lacks shell access, and presents cost unpredictability issues. Microsoft Azure Cosmos DB users experience pricing complexity due to high initial costs based on RUs and face challenges with integration and a steep learning curve in optimization.

Ease of Deployment and Customer Service: Both products are primarily deployed on public cloud platforms. Amazon RDS is noted for its straightforward initial setup, although technical support responsiveness and costs receive mixed reviews. Microsoft Azure Cosmos DB is commended for its stability and technical support, albeit with complexity in its documentation and setup that can be challenging for new users.

Pricing and ROI: Amazon RDS uses a flexible pay-as-you-go model, though costs can escalate unexpectedly. It requires careful management to optimize financial outcomes, showing generally positive ROI. Cosmos DB's pricing tied to request units leads to cost unpredictability, favoring those who understand resource management in reserving capacity. Both solutions require detailed planning to maximize cost-efficiency and prevent unforeseen expenses.

To learn more, read our detailed Amazon RDS vs. Microsoft Azure Cosmos DB Report (Updated: December 2025).

Buyer's Guide

Amazon RDS vs. Microsoft Azure Cosmos DB

December 2025

Download the complete report

Helped 881,082 peers since 2012

Review summaries and opinions

We asked business professionals to review the solutions they use. Here are some excerpts of what they said:

ROI

Sentiment score

2.6

Organizations benefit financially from Amazon RDS's cost-effectiveness, agility, and scalability, despite varying results and AWS expense concerns.

Sentiment score

6.2

Organizations report cost savings and efficiency with Azure Cosmos DB, but some experience complexity and difficulty achieving expected savings.

No quotes available

For more quotes and insights, download the Amazon RDS report

Getting an MVP of that project would have taken six to eight months, but because we had an active choice of using Azure Cosmos DB and other related cloud-native services of Azure, we were able to get to an MVP stage in a matter of weeks, which is six weeks.

MichaelJohn

Director | Data & AI at a tech services company with 11-50 employees

You can react quickly and trim down the specs, memory, RAM, storage size, etc. It can save about 20% of the costs.

Bernard Parinas

Co-Founder at arpa

When I have done comparisons or cost calculations, I have sometimes personally seen as much as 25% to 30% savings.

Alexander Hughes

Solutions Architect at CompuNet

For more quotes and insights, download the Microsoft Azure Cosmos DB report

Customer Service

Sentiment score

6.8

Amazon RDS support varies by level and location; premium is efficient, but US standard support often lacks expertise.

Sentiment score

6.7

Microsoft Azure Cosmos DB support is generally responsive, but experiences vary, with premium users often reporting better satisfaction.

The documentation is quite good.

Kenan Çiftçi

Corporate Database Architect at a tech services company with 201-500 employees

The official AWS technical support for Amazon RDS is helpful, providing 24/7 assistance for all business support cases with tools such as the health dashboard and AWS trusted advisor.

Baqir Sajjad

AWS Architect at Virtual University

I would rate the support from AWS very high, maybe nine, but it also depends on what kind of support you have signed in your contract, whether the premium support or the standard support.

reviewer2592669

Director Software Engineer at a computer software company with 10,001+ employees

For more quotes and insights, download the Amazon RDS report

Premier Support has deteriorated compared to what it used to be, especially for small to medium-sized customers like ours.

reviewer2595951

Head of IT, Infrastructure, Operations & Applications Development at a manufacturing company with 201-500 employees

The response was quick.

Joel Hulen

Lead Cloud Architect at Solliance, Inc

I would rate customer service and support a nine out of ten.

MichaelJohn

Director | Data & AI at a tech services company with 11-50 employees

For more quotes and insights, download the Microsoft Azure Cosmos DB report

Scalability Issues

Sentiment score

7.1

Amazon RDS is praised for its scalability and reliability, though some express minor concerns with large dataset management.

Sentiment score

7.7

Microsoft Azure Cosmos DB offers scalable, flexible solutions with efficient cost management, ideal for large enterprises, despite partition size limits.

Its automated scaling, both in storage and instances, is vital as it eliminates manual interventions.

Samuel Ebite

AICE Graduate at alx_africa

The installation of Amazon RDS is quite easy and quite scalable.

reviewer2592669

Director Software Engineer at a computer software company with 10,001+ employees

Despite being a strong feature, scalability could be improved due to the lack of full functionality in autoscaling.

reviewer2668191

VP engineering at a computer software company with 1,001-5,000 employees

For more quotes and insights, download the Amazon RDS report

The system scales up capacity when needed and scales down when not in use, preventing unnecessary expenses.

Hashir Ali Shuja

Associate Software Architect at a tech vendor with 51-200 employees

We like that it can auto-scale to demand, ensuring we only pay for what we use.

Tiago Duarte

CTO at Stellium Consulting

We have had no issues with its ability to search through large amounts of data.

reviewer2678751

Full Stack Software Developer at a tech vendor with 10,001+ employees

For more quotes and insights, download the Microsoft Azure Cosmos DB report

Stability Issues

Sentiment score

8.1

Amazon RDS is praised for reliability, performance, and uptime with minimal issues, especially with Multi-AZ enhancing stability.

Sentiment score

7.6

Microsoft Azure Cosmos DB offers high availability and reliability, with users praising its scalability, integration, and minimal downtime.

Amazon RDS is very stable when deployed correctly across different zones with the right configurations.

Samuel Ebite

AICE Graduate at alx_africa

It is a stable product overall, with very few issues.

reviewer2668191

VP engineering at a computer software company with 1,001-5,000 employees

Amazon RDS is quite stable, and the SLAs are sort of 99.98%.

reviewer2592669

Director Software Engineer at a computer software company with 10,001+ employees

For more quotes and insights, download the Amazon RDS report

We have multiple availability zones, so nothing goes down.

reviewer2596239

Hands on user at a manufacturing company with 10,001+ employees

Azure Cosmos DB would be a good choice if you have to deploy your application in a limited time frame and you want to auto-scale the database across different applications.

HarshitGaur

Associate Data Analytics L1 at a computer software company with 10,001+ employees

I would rate it a ten out of ten in terms of availability and latency.

Aroosh Kumar

Azure Consultant at Deloitte

For more quotes and insights, download the Microsoft Azure Cosmos DB report

Room For Improvement

Amazon RDS users seek improvements in security, documentation, scalability, integration, and support, with enhanced customization and cost reduction.

Microsoft Azure Cosmos DB needs improvements in query complexity, API integration, performance, documentation, cost management, and user-interface enhancements.

Simplifying migration for those transitioning from on-premises to cloud environments.

Samuel Ebite

AICE Graduate at alx_africa

Having native Change Data Capture (CDC) support would be beneficial, allowing for seamless integration with Kafka without relying on external technologies like Debezium.

reviewer2668191

VP engineering at a computer software company with 1,001-5,000 employees

Enabling performance insights to view query formats where the bottlenecks occur, identifying the fixes, slow queries, and missing indexes.

Baqir Sajjad

AWS Architect at Virtual University

For more quotes and insights, download the Amazon RDS report

We must ensure data security remains the top priority.

Mohamed Ait Salah

Cloud Solutions Architect and Microsoft Principal Consultant for EMEA at a tech vendor with 10,001+ employees

You have to monitor the Request Units.

Bernard Parinas

Co-Founder at arpa

The dashboard could include more detailed RU descriptions, IOPS, and compute metrics.

Fabien GOUINEAU

Architecte Cloud at Visiativ SA

For more quotes and insights, download the Microsoft Azure Cosmos DB report

Setup Cost

Amazon RDS pricing is usage-dependent and cost-effective, offering savings on admin costs but can be expensive compared to alternatives.

Azure Cosmos DB pricing varies, appreciated for scalability but seen as costly with high demand and complex environments.

While Azure provides great services, long-term plans on AWS are 20% to 30% cheaper.

Karthikeyan Katkam

AWS Engineer at Neurolov.ai

I find the pricing of Amazon RDS fair, as AWS operates on a pay-for-what-you-use model.

Samuel Ebite

AICE Graduate at alx_africa

I rate the price for Amazon as eight on a scale from one to ten.

Kenan Çiftçi

Corporate Database Architect at a tech services company with 201-500 employees

For more quotes and insights, download the Amazon RDS report

Initially, it seemed like an expensive way to manage a NoSQL data store, but so many improvements that have been made to the platform have made it cost-effective.

Joel Hulen

Lead Cloud Architect at Solliance, Inc

Cosmos DB is expensive, and the RU-based pricing model is confusing.

Christian Gomez Rua

IT Data Architect & Manager at Ternium Mexico S.A. de C.V.

Cosmos DB is great compared to other databases because we can reduce the cost while doing the same things.

Rusty Coulbourne

Lead Software Architect at CPower

For more quotes and insights, download the Microsoft Azure Cosmos DB report

Valuable Features

Amazon RDS provides scalability, security, and flexibility with multi-engine support and simplified operations for diverse applications.

Microsoft Azure Cosmos DB is valued for scalability, ease of integration, global distribution, security, and support for diverse applications.

Amazon RDS provides data encryption using services like KMS, crucial for securing high-sensitive data and meeting compliance requirements such as HIPAA or PCI DSS.

Samuel Ebite

AICE Graduate at alx_africa

Database management is effective in Amazon RDS because it offers automated backups, high availability, read replicas, and support from multiple database engineers, while also providing security, monitoring and metrics, scalability.

Baqir Sajjad

AWS Architect at Virtual University

In some cases, we are using the read replica feature, and it does improve our application performance because we do not allow any downstream system to come to the main storage or main databases and perform a query.

reviewer2592669

Director Software Engineer at a computer software company with 10,001+ employees

For more quotes and insights, download the Amazon RDS report

The most valuable feature of Microsoft Azure Cosmos DB is its real-time analytics capabilities, which allow for turnaround times in milliseconds.

reviewer2227599

Vice President, Machine Learning at a healthcare company with 10,001+ employees

Performance and security are valuable features, particularly when using Cosmos DB for MongoDB emulation and NoSQL.

Christian Gomez Rua

IT Data Architect & Manager at Ternium Mexico S.A. de C.V.

The performance and scaling capabilities of Cosmos DB are excellent, allowing it to handle large workloads compared to other services such as Azure AI Search.

Tiago Duarte

CTO at Stellium Consulting

For more quotes and insights, download the Microsoft Azure Cosmos DB report

Categories and Ranking

Amazon RDS

Ranking in Database as a Service (DBaaS)

2nd

Average Rating

8.4

Reviews Sentiment

6.7

Number of Reviews

Ranking in other categories

Relational Databases Tools (9th)

Microsoft Azure Cosmos DB

Ranking in Database as a Service (DBaaS)

4th

Average Rating

8.2

Reviews Sentiment

6.9

Number of Reviews

109

Ranking in other categories

NoSQL Databases (2nd), Managed NoSQL Databases (1st), Vector Databases (1st)

Mindshare comparison

As of January 2026, in the Database as a Service (DBaaS) category, the mindshare of Amazon RDS is 14.8%, down from 25.3% compared to the previous year. The mindshare of Microsoft Azure Cosmos DB is 4.1%, up from 0.8% compared to the previous year. It is calculated based on PeerSpot user engagement data.

Database as a Service (DBaaS) Market Share Distribution
Product	Market Share (%)
Amazon RDS	14.8%
Microsoft Azure Cosmos DB	4.1%
Other	81.1%

Database as a Service (DBaaS)

Featured Reviews

reviewer2592669

Director Software Engineer at a computer software company with 10,001+ employees

Positive experiences with database services, with minor room for feature enhancements observed

I don't really see any disadvantages of Amazon RDS. With Oracle, I think AWS doesn't provide the RAC stability. If you have Oracle installed in your own data centers, you can set up various clusters and we can set up the RACs, but in Amazon RDS, we cannot have the RAC feature of Oracle. They could add that feature. Amazon RDS has limitations regarding RAC. If we talk about installing Oracle in RDS, we cannot have the RAC, but if you deploy Oracle on GCP, then there is probably the RAC feature available. I observed that around two or three years back, but I'm not sure whether they have added the RAC feature in AWS. Amazon RDS is expensive compared to GCP. GCP also has the same features, and although it is quite extensive and feature-rich, I see Amazon RDS as slightly expensive compared to other clouds.

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reviewer2724105

Senior Director of Product Management at a tech vendor with 1,001-5,000 employees

Provides super sharp latency, excellent availability, and the ability to effectively manage costs across different tenants

For integrating Microsoft Azure Cosmos DB with other Azure products or other products, there are a couple of challenges with the current system. Right now, the vectors are stored as floating-point numbers within the NoSQL document, which makes them inefficiently large. This leads to increased storage space requirements, and searching through a vast number of documents in the vector database becomes quite costly in terms of RUs. While the integration works well, the expense associated with it is relatively high. I would really like to see a reduction in costs for their vector search, as it is currently on the expensive side. The areas for improvement in Microsoft Azure Cosmos DB are vector pricing and vector indexing patterns, which are unintuitive and not well described. I would also like to see the parameters of Fleet Spaces made more powerful, as currently, it's somewhat lightweight. I believe they've made those changes intentionally to better understand the cost model. However, we would like to take a more aggressive approach in using it. One of the most frustrating aspects of Microsoft Azure Cosmos DB right now is that you can only store one vector per document. Additionally, you must specify the configuration of that vector when you create an instance of Microsoft Azure Cosmos DB. Once the database is set up, you can't change the vector configuration, which is incredibly limiting for experimentation. You want the ability to try different settings and see how they perform, as there are numerous use cases for storing more than one vector in a document. While interoperability within the vector database is acceptable—for example, I can search for vectors—I still desire a richer set of configuration options.

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Top Industries

By visitors reading reviews

No data available

Legal Firm

13%

Financial Services Firm

11%

Comms Service Provider

Manufacturing Company

Company Size

By reviewers

Large Enterprise

Midsize Enterprise

Small Business

By reviewers
Company Size	Count
Small Business	22
Midsize Enterprise	15
Large Enterprise	23

By reviewers
Company Size	Count
Small Business	33
Midsize Enterprise	21
Large Enterprise	58

Questions from the Community

What do you like most about Amazon RDS?

The product's installation phase is easy.

See all answers

What is your experience regarding pricing and costs for Amazon RDS?

The pricing for Amazon RDS is reasonable.

See all answers

What needs improvement with Amazon RDS?

Currently, I cannot think of any major improvements. Perhaps more platforms in terms of database engine versions would be beneficial. Right now, Amazon RDS supports MySQL and PostgreSQL, but there ...

See all answers

What do you like most about Microsoft Azure Cosmos DB?

The initial setup is simple and straightforward. You can set up a Cosmos DB in a day, even configuring things like availability zones around the world.

See all answers

What is your experience regarding pricing and costs for Microsoft Azure Cosmos DB?

Microsoft Azure Cosmos DB's pricing model has aligned with my budget expectations because I can tune the RU as I need to, which helps a lot. Microsoft Azure Cosmos DB's dynamic auto-scale or server...

See all answers

What needs improvement with Microsoft Azure Cosmos DB?

I have not utilized Microsoft Azure Cosmos DB multi-model support for handling diverse data types. I'm not in the position to decide if clients will use Microsoft Azure Cosmos DB or any other datab...

See all answers

Comparisons

MongoDB Atlas vs Amazon RDS

Compared 20% of the time

Google Cloud SQL vs Amazon RDS

Compared 15% of the time

Microsoft Azure SQL Database vs Amazon RDS

Compared 13% of the time

Oracle Database as a Service vs Amazon RDS

Compared 12% of the time

Oracle Exadata Cloud at Customer vs Amazon RDS

Compared 5% of the time

More Amazon RDS Competitors

Pinecone vs Microsoft Azure Cosmos DB

Compared 7% of the time

Chroma vs Microsoft Azure Cosmos DB

Compared 7% of the time

Amazon DynamoDB vs Microsoft Azure Cosmos DB

Compared 6% of the time

Neo4j Graph Database vs Microsoft Azure Cosmos DB

Compared 6% of the time

MongoDB Enterprise Advanced vs Microsoft Azure Cosmos DB

Compared 6% of the time

More Microsoft Azure Cosmos DB Competitors

Product Reports

Buyer's Guide

Amazon RDS

January 2026

Download Amazon RDS product report

Buyer's Guide

Microsoft Azure Cosmos DB

January 2026

Download Microsoft Azure Cosmos DB product report

Also Known As

RDS

Microsoft Azure DocumentDB, MS Azure Cosmos DB

Overview

Amazon Relational Database Service (Amazon RDS) is a web service that makes it easier to set up, operate, and scale a relational database in the cloud. It provides cost-efficient, resizeable capacity for an industry-standard relational database and manages common database administration tasks.

Amazon Web Services (AWS)

Microsoft Azure Cosmos DB offers scalable, geo-replicated, multi-model support with high performance and low latency. It provides seamless Microsoft service integration, benefiting those needing flexible NoSQL, real-time analytics, and automatic scaling for diverse data types and quick global access.

Azure Cosmos DB is designed to store, manage, and query large volumes of both unstructured and structured data. Its NoSQL capabilities and global distribution are leveraged by organizations to support activities like IoT data management, business intelligence, and backend databases for web and mobile applications. While its robust security measures and availability are strengths, there are areas for improvement such as query complexity, integration with services like Databricks and MongoDB, documentation clarity, and performance issues. Enhancements in real-time analytics, API compatibility, cross-container joins, and indexing capabilities are sought after. Cost management, optimization tools, and better support for local development also require attention, as do improvements in user interface and advanced AI integration.

What are the key features of Azure Cosmos DB?

Scalability: Effortlessly handles scaling for large workloads.
Geo-replication: Provides global data access with low latency.
Multi-model Support: Compatible with diverse data types.
NoSQL Flexibility: Offers a non-relational database experience.
Real-time Analytics: Facilitates data-driven decision-making.
Automation: Simplifies scaling and maintenance processes.

What benefits can users expect from Cosmos DB?

High Performance: Ensures rapid processing and low latency.
Ease of Use: Features a user-friendly interface enhancing deployment speed.
Seamless Integration: Connects effortlessly with Microsoft services.
Security: Offers robust measures to protect data integrity.
Consistent Availability: Ensures continuous access to data worldwide.

Industries use Azure Cosmos DB to support business intelligence and IoT data management, using its capabilities for backend databases in web and mobile applications. The platform's scalability and real-time analytics benefit sectors like finance, healthcare, and retail, where managing diverse datasets efficiently is critical.

Microsoft

Sample Customers

Edmodo

TomTom, KPMG Australia, Bosch, ASOS, Mercedes Benz, NBA, Zero Friction, Nederlandse Spoorwegen, Kinectify

Buyer's Guide

Amazon RDS vs. Microsoft Azure Cosmos DB

December 2025

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