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Faiss 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

Faiss
Ranking in Vector Databases
13th
Average Rating
8.0
Reviews Sentiment
3.3
Number of Reviews
3
Ranking in other categories
Open Source Databases (12th)
Microsoft Azure Cosmos DB
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), NoSQL Databases (2nd), Managed NoSQL Databases (1st)
 

Mindshare comparison

As of July 2026, in the Vector Databases category, the mindshare of Faiss is 4.3%, down from 6.2% compared to the previous year. The mindshare of Microsoft Azure Cosmos DB is 6.1%, up from 4.0% compared to the previous year. It is calculated based on PeerSpot user engagement data.
Vector Databases Mindshare Distribution
ProductMindshare (%)
Microsoft Azure Cosmos DB6.1%
Faiss4.3%
Other89.6%
Vector Databases
 

Featured Reviews

Kalindu Sekarage - PeerSpot reviewer
Senior Software Engineer
Integration improves accuracy and supports token-level embedding
The best features FAISS offers for my team include seamless integration with Colbert and the ability to use FAISS via the Ragatouille framework, which is tailor-made for using the Colbert model. Feature-wise, FAISS allows for more accurate result retrieval, and retrieval speed is also good when comparing the index size. Regarding features, I also emphasize that the usability of FAISS is very seamless, particularly its integration with Colbert and Ragatouille. FAISS has positively impacted my organization by helping us increase the accuracy of retrieval documents; when we store documents in token-level embedding, the accuracy will be high. Additionally, we do not need any external server to host FAISS, allowing us to integrate it with our backend framework, making it a very flexible framework.
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

"The product has better performance and stability compared to one of its competitors."
"I used Faiss as a basic database."
"It is a NoSQL database."
"The ability to scale automatically is very valuable. Additionally, multi-region support automatically synchronizing to a different region for multi-region applications is a cool feature. It's more of a lift with other databases to configure that extra region and set up replication, even if it's on the cloud. With Azure, it's just a button click. It's that simple."
"The best features of Microsoft Azure Cosmos DB are the way it maintains the data in partitions and its retention policies."
"Its wide support to the ecosystem is valuable. We can use this database with a lot of use cases, and that's one of the reasons why we prefer it. We have a lot of vendors, databases, and use cases, and wherever possible, we are trying to standardize databases. It is also secure."
"The feature I have found most valuable in Microsoft Azure Cosmos DB is its scalability and speed."
"Latency and availability are incredible."
"Cosmos DB makes life easier because if we want to use Mongo-type data, or Cassandra-type data, or maybe even just a simple cable storage-type data, then graph, there are multiple ways to do this."
"Microsoft Azure Cosmos DB is very easy to use once you understand the process, and we have a very good team; because it is more costly compared to other services, the Microsoft product team takes customers very seriously and if any issue arises, they immediately join calls with customers to troubleshoot problems."
 

Cons

"It would be beneficial if I could set a parameter and see different query mechanisms being run."
"One of the drawbacks of Faiss is that it works only in-memory. If it could provide separate persistent storage without relying on in-memory, it would reduce the overhead."
"It could be more accessible for handling larger data sets."
"Microsoft Azure Cosmos DB's pricing model is complicated, which people don't understand."
"We had some performance issues with a data segregation query. We worked closely with Microsoft to solve the problem of performance where, for example, one query had a delay of almost two or three minutes for this one use case. Microsoft tried to improve the product, but in the end, the solution was to change to MongoDB. MongoDB had better performance."
"Cosmos DB is expensive, and the RU-based pricing model is confusing."
"One area for improvement is the ease of writing SQL queries and stored procedures in Microsoft Azure Cosmos DB. Writing an SQL query and a stored procedure on top of that is a little challenging."
"New features can be included and its stability can be further improved."
"To show this in real time, we need a live connection that automatically updates in response to new records being inserted. This automated updating feature is lacking in Microsoft Azure Cosmos DB compared to Databricks."
"At this stage, we would like more enterprise support. We use MongoDB a lot, and we're trying to get rid of MongoDB. So, I would like to see more features in the Cosmos DB API for MongoDB space."
"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."
 

Pricing and Cost Advice

"It is an open-source tool."
"Faiss is an open-source solution."
"It is expensive. The moment you have high availability options and they are mixed with the type of multitenant architecture you use, the pricing is on the higher end."
"Cosmos DB gave us three accounts for $400. We pay according to the usage."
"Pricing is mid- to high-end."
"Its price is very good for the basic stuff. When you go to a more complicated use case, especially when you need replication and availability zones, it gets a little costly."
"Its pricing structure is quite flexible."
"Azure is a pay as you go subscription."
"Microsoft Azure Cosmos DB's licensing costs are monthly."
"Cosmos DB is a highly cost-optimized solution when used correctly."
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Top Industries

By visitors reading reviews
Financial Services Firm
15%
Comms Service Provider
10%
Manufacturing Company
10%
Computer Software Company
9%
Financial Services Firm
11%
Legal Firm
11%
Comms Service Provider
8%
Manufacturing Company
8%
 

Company Size

By reviewers
Large Enterprise
Midsize Enterprise
Small Business
No data available
By reviewers
Company SizeCount
Small Business33
Midsize Enterprise22
Large Enterprise58
 

Questions from the Community

What is your experience regarding pricing and costs for Faiss?
I did not purchase FAISS through the AWS Marketplace because FAISS is an open-source product. My experience with pricing, setup cost, and licensing is straightforward, as there is no cost for acqui...
What needs improvement with Faiss?
I currently do not think there is anything to be improved based on our experience, as Faiss performs as we expected for our workflow. I would like to see improvement in the fact that FAISS currentl...
What is your primary use case for Faiss?
My main use case for FAISS is in a retrieval-augmented generation project using it with OpenAI, where we use FAISS to store our embeddings created by the Colbert model and for retrieval as well. In...
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. Facebook 2. Airbnb 3. Pinterest 4. Twitter 5. Microsoft 6. Uber 7. LinkedIn 8. Netflix 9. Spotify 10. Adobe 11. eBay 12. Dropbox 13. Yelp 14. Salesforce 15. IBM 16. Intel 17. Nvidia 18. Qualcomm 19. Samsung 20. Sony 21. Tencent 22. Alibaba 23. Baidu 24. JD.com 25. Rakuten 26. Zillow 27. Booking.com 28. Expedia 29. TripAdvisor 30. Rakuten 31. Rakuten Viber 32. Rakuten Ichiba
TomTom, KPMG Australia, Bosch, ASOS, Mercedes Benz, NBA, Zero Friction, Nederlandse Spoorwegen, Kinectify
Find out what your peers are saying about Faiss vs. Microsoft Azure Cosmos DB and other solutions. Updated: June 2026.
906,852 professionals have used our research since 2012.