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Cassandra vs Microsoft Azure Cosmos DB comparison

 

Comparison Buyer's Guide

Executive SummaryUpdated on Jan 25, 2026

Review summaries and opinions

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

Categories and Ranking

Cassandra
Ranking in NoSQL Databases
5th
Ranking in Vector Databases
12th
Average Rating
8.0
Reviews Sentiment
6.0
Number of Reviews
25
Ranking in other categories
No ranking in other categories
Microsoft Azure Cosmos DB
Ranking in NoSQL Databases
1st
Ranking in Vector Databases
1st
Average Rating
8.2
Reviews Sentiment
6.9
Number of Reviews
109
Ranking in other categories
Database as a Service (DBaaS) (3rd), Managed NoSQL Databases (1st)
 

Mindshare comparison

As of August 2026, in the NoSQL Databases category, the mindshare of Cassandra is 8.2%, down from 9.7% compared to the previous year. The mindshare of Microsoft Azure Cosmos DB is 6.0%, up from 5.1% compared to the previous year. It is calculated based on PeerSpot user engagement data.
NoSQL Databases Mindshare Distribution
ProductMindshare (%)
Microsoft Azure Cosmos DB6.0%
Cassandra8.2%
Other85.8%
NoSQL Databases
 

Featured Reviews

Monirul Islam Khan - PeerSpot reviewer
Head, Data Integration & Management at a non-profit with 10,001+ employees
Has maintained secure document storage and efficient data distribution with peer-to-peer architecture
The functions or features in Cassandra that I have found most valuable are that it is a distributed system similar to Mongo. It's good enough for comparison with another SQL database, so it's smooth and organized for distributed database system. The peer-to-peer architecture in Cassandra is helpful for network decentralization, and I have already introduced that feature. Cassandra features in peer-to-peer as well as another monitoring, so basically, it's good enough for our service. The tunable consistency level in Cassandra is good, and we are using that feature already. In terms of built-in caching and lightweight transactions in Cassandra, the transaction level is good, and it's optimized, so there are no more issues in that database. Based on my experience, Cassandra is good for document management system, as well as distributed database system, and the automatic recovery process is there. Additionally, the database monitoring system or auditing system is well-comparable with other database systems, so we are actually happy to be using this Cassandra database.
Michael Hasenfang - PeerSpot reviewer
Director, Platform Engineering - Infrastructure Systems and Automation at a computer software company with 1,001-5,000 employees
Collecting compliance data has become more efficient while managing unstructured inputs for reporting
The features that I find most valuable within Microsoft Azure Cosmos DB are probably the cost, as the cost optimization is good. The storage and queryability are good for what we're doing; it's a lot of unstructured data, so having a platform to put that in and then be able to harvest that data out for the reporting we do is essential. In terms of cost saving, it was probably easily 30 to 40% cheaper than doing a standard SQL, which is what we saw just on piloting and getting in there. We were initially thinking 20 to 25%, but we were probably more at the 35 to 40%. We are using Microsoft Azure Cosmos DB's hybrid search today. The value that it has added to my AI or search workloads is that I think it's optimized that process and made it easier. We have a lot of unstructured data coming from different dissimilar systems and different data sources, so correlating those things together and making sense of it has been very beneficial. Microsoft Azure Cosmos DB has had pretty good performance with searching through large amounts of data; it's been fast, and we haven't seen a lot of performance degradation while building larger queries and bringing in a large set of data. The dynamic auto-scale or serverless model from Microsoft Azure Cosmos DB has helped reduce costs and operational effort; however, it's hard to quantify how that plays out since you're using a shared service. It shifts my focus away from building, managing, and upgrading to adding value.

Quotes from Members

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

Pros

"Cassandra has some features that are more useful for specific use cases where you have time series where you have huge amounts of writes. That should be quick, but not specifically the reads. We needed to have quicker reads and writes and this is why we are using Cassandra right now."
"Our primary use case for the solution is testing."
"The most valuable features of this solution are its speed and distributed nature."
"A consistent solution."
"The solution provided us with more than 100K PNRs a second and because the company was international there was a heavy data write, and at the same time a heavy data read."
"Overall, I would rate Cassandra as nine because of its fast writes, which really suit our use cases mostly."
"Cassandra is a stable solution."
"The use of Cassandra in real-time data analytics has been pivotal for our e-commerce platform. As our platform operates 24/7, providing services to sellers and customers alike, the need for real-time updates is paramount."
"We value the replication and regional availability features that Cosmos DB provides. The replication includes read replicas and write replicas. The recent addition of vectorization and similarity comparisons add values for AI workloads. 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."
"Latency and availability are incredible."
"We achieved a strong return on investment."
"Microsoft Azure Cosmos DB offers the response times needed for advanced analytics applications."
"It works reasonably fast. You can retain the original format of the document as received by the third-party system."
"The scalability and ease of use with the APIs of Microsoft Azure Cosmos DB have allowed us to meet our customers' expectations pretty easily with little barrier to entry."
"The efficiency of search capabilities is significant, particularly when it comes to the flexibility of conducting in-depth, almost recursive searches that are both efficient and cost-effective."
"Azure Cosmos DB helped improve the quality of our search results."
 

Cons

"The interface could definitely be improved. It's a technical database and for me the features are not user friendly."
"Fine-tuning was a bit of a challenge."
"Cassandra could be more user-friendly like MongoDB."
"The disc space is lacking. You need to free it up as you are working."
"The solution is limited to a linear performance."
"Some issues arise from our vendors like Apache slowness and distribution or load balancing from HAProxy, which should better handle consumption for high-level concurrency."
"Row-level locking is not available; might be very helpful in update use cases."
"Batching bulk data can cause performance issues."
"One of the most frustrating aspects of Microsoft Azure Cosmos DB right now is that you can only store one vector per document."
"The pricing of the solution is an area with certain shortcomings."
"The built-in integration of the solution is tight."
"In the long run, there should be an addition of more features, especially because this space is evolving quickly. It all boils down to how many more features you are adding, how many integrations you are supporting, and how many more APIs you have that are standard APIs."
"Overall, it works very well and fits the purpose regardless of the target application. However, by default, there is a threshold to accommodate bulk or large requests. You have to monitor the Request Units. If you need more data for a particular query, you need to increase the Request Units."
"I had a challenging experience implementing the emulator with a Mac. I had to install the emulator in a Docker container because it is not natively compatible. A significant amount of time was spent researching how to enable HTTPS communication when connecting the container and the emulator."
"There aren't any specific areas that need improvement, but if there were a way to achieve the right cosine similarity score without extensive testing, that would be very beneficial."
"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."
 

Pricing and Cost Advice

"We pay for a license."
"I don't have the specific numbers on pricing, but it was fairly priced."
"Cassandra is a free open source solution, but there is a commercial version available called DataStax Enterprise."
"There are licensing fees that must be paid, but I'm not sure if they are paid monthly or yearly."
"I use the tool's open-source version."
"We are using the open-source version of Cassandra, the solution is free."
"Most customers like the flexibility of the pricing model, and it has not been an issue. They can start small, and the cost grows with adoption, allowing efficient management of the budget. Its pricing model has not been a concern at all for any of our customers. They understand it. It is simple enough to understand. Oftentimes, it is hard to forecast the RUs, but, in general, it has been fine."
"Microsoft Azure Cosmos DB pricing is based on RUs. Reading 1 KB document costs one RU, whereas writing one document costs five RUs. Pricing for querying depends on the complexity of the query. If you increase the document size, it will automatically increase the RU cost."
"We are not consuming so much yet since we are at the beginning of using this solution. I would rate the pricing of Microsoft Azure Cosmos DB a six out of ten."
"The cost is the biggest limitation of this solution."
"It is cost-efficient as long as you understand the right setup to optimize usage. Knowing the data needs of the organization and adjusting the Microsoft Azure Cosmos DB usage accordingly helps save costs, but if you don't know, you could end up spending more than necessary."
"Cosmos should be cheaper. We actually intend to stop using it in the near future because the price is too high."
"The solution is very expensive."
"The pricing for Cosmos DB has improved, particularly with the new pricing for Autoscale."
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Top Industries

By visitors reading reviews
Financial Services Firm
16%
Comms Service Provider
8%
Construction Company
8%
Performing Arts
5%
Financial Services Firm
11%
Legal Firm
11%
Comms Service Provider
8%
Manufacturing Company
8%
 

Company Size

By reviewers
Large Enterprise
Midsize Enterprise
Small Business
By reviewers
Company SizeCount
Small Business9
Midsize Enterprise2
Large Enterprise14
By reviewers
Company SizeCount
Small Business33
Midsize Enterprise22
Large Enterprise58
 

Questions from the Community

What is your experience regarding pricing and costs for Cassandra?
The pricing for Cassandra is a little bit high, so it would be better for our community services if they consider community pricing for any non-profit organization like an NGO or other things. It w...
What needs improvement with Cassandra?
Regarding areas of improvement for Cassandra, currently, we are not facing significant issues. Some issues arise from our vendors like Apache slowness and distribution or load balancing from HAProx...
What is your primary use case for Cassandra?
My use case for Cassandra is for a document and other unstructured data management system as well as structured data for ultra-poor member community edition, community members' PII information, so ...
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...
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...
What is your primary use case for Microsoft Azure Cosmos DB?
We have a very large team of developers who develop a solution for our customers. In the part where they need some infrastructure on Microsoft Azure, we deploy entire environments of different type...
 

Also Known As

No data available
Microsoft Azure DocumentDB, MS Azure Cosmos DB
 

Overview

 

Sample Customers

1. Apple 2. Netflix 3. Facebook 4. Instagram 5. Twitter 6. eBay 7. Spotify 8. Uber 9. Airbnb 10. Adobe 11. Cisco 12. IBM 13. Microsoft 14. Yahoo 15. Reddit 16. Pinterest 17. Salesforce 18. LinkedIn 19. Hulu 20. Airbnb 21. Walmart 22. Target 23. Sony 24. Intel 25. Cisco 26. HP 27. Oracle 28. SAP 29. GE 30. Siemens 31. Volkswagen 32. Toyota
TomTom, KPMG Australia, Bosch, ASOS, Mercedes Benz, NBA, Zero Friction, Nederlandse Spoorwegen, Kinectify
Find out what your peers are saying about Cassandra vs. Microsoft Azure Cosmos DB and other solutions. Updated: August 2026.
908,858 professionals have used our research since 2012.