Softwr

Databases · head to head

DataStax vs FaunaDB

DataStax logo

DataStax

Databases

The real-time data company for AI applications

From
Free
Rated
-
Full reviewWebsite
FaunaDB logo

FaunaDB

Databases

Document-relational database whose hosted service closed in 2025 and whose core is now unmaintained Apache 2.0 code.

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: DataStax dataStax's own Astra DB documentation states the Enterprise plan is an annual, contract-based plan with negotiated pricing, meaning list prices are not published for that tier; FaunaDB the hosted service was wound down in 2025, so there is no managed Fauna to buy; every remaining user either operates a JVM cluster themselves or migrates, and both are projects rather than tasks.
  • They diverge on capability: DataStax covers Cassandra Compatible, FaunaDB covers Document-relational model.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which DataStax and FaunaDB actually diverge.

Attributes where DataStax and FaunaDB differ
AttributeDataStaxFaunaDB
PlatformsWeb, Aws, Azure, GcpWeb
Founded20102012

Identical on both: starting price (Free), pricing model (freemium), free tier (Yes), user rating (Not yet rated), category (Databases).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in DataStax

  • Cassandra Compatible
  • Vector Search
  • Serverless
  • Multi-cloud
  • Streaming
  • CDC
  • GraphQL API
  • LangChain

Only in FaunaDB

  • Document-relational model
  • FQL v10
  • Distributed ACID transactions
  • HTTPS access
  • User-defined functions
  • Attribute-based access control
  • Document history
  • Event streaming

What people use each for

The jobs each tool is most often brought in to do.

DataStax

  • Real-time applicationsnot FaunaDB
  • Content managementnot FaunaDB
  • User profilesnot FaunaDB
  • Mobile backendsnot FaunaDB
  • Cachingnot FaunaDB

FaunaDB

  • Keeping an existing Fauna-backed application alive on self-hosted infrastructure while a migration is planned and fundednot DataStax
  • Extracting historical data from a Fauna dataset that can no longer be reached through the hosted APInot DataStax
  • Studying a production implementation of deterministic distributed transactions, since the full server source is now readable under Apache 2.0not DataStax
  • Forking the engine deliberately, where an organisation has JVM and distributed-systems staff and wants a document-relational store it fully controlsnot DataStax

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

DataStax

  • DataStax's own Astra DB documentation states the Enterprise plan is an annual, contract-based plan with negotiated pricing, meaning list prices are not published for that tier
  • DataStax's Astra DB documentation directs Standard plan customers to IBM's watsonx.data pricing for exact consumption-based rates following the DataStax/IBM deal, rather than publishing them on DataStax's own site

FaunaDB

  • The hosted service was wound down in 2025, so there is no managed Fauna to buy; every remaining user either operates a JVM cluster themselves or migrates, and both are projects rather than tasks.
  • The open-sourced repository has had no substantive activity since May 2025 and the drivers were frozen alongside it, so you inherit responsibility for security patches in a Scala distributed database that almost nobody else is running.
  • FQL has no wire or dialect compatibility with anything else, so migrating off is a rewrite of every query, index and access rule in the application rather than a data export.
  • No BI tool, ORM or CDC connector speaks FQL, so reporting and analytics always required exporting the data first, and that export tooling is now also unmaintained.
  • The community was small before the shutdown and has dispersed since, so operational answers, tuning advice and people who have run a Fauna cluster in anger are all scarce when something breaks.

Pricing, plan by plan

DataStax

Free
  • FreeFree
    • 5GB storage
    • 40M read/write ops
    • Vector search
  • Pay As You GoFree
    • Usage-based pricing
    • Multi-region
    • Enterprise support

FaunaDB

Free
  • FreeFree
    • 100K read ops
    • 50K write ops
    • 1GB storage
  • Pro$25/month
    • Pay per use
    • Priority support
    • Advanced features

Which should you pick?

Choose DataStax if

  • You need cassandra compatible.
  • You want to start without paying.
  • You work on Web, Aws, Azure, Gcp.
  • You also want vector search.
DataStax review

Choose FaunaDB if

  • You need document-relational model.
  • You want to start without paying.
  • You also want fql v10.
FaunaDB review

Questions people ask

Is DataStax or FaunaDB better?
Neither clearly leads. DataStax starts at Free and FaunaDB at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, DataStax or FaunaDB?
DataStax starts at Free and FaunaDB at Free.
Does DataStax or FaunaDB run on more platforms?
DataStax runs on Web, Aws, Azure, Gcp. FaunaDB runs on Web.
Can I use DataStax for free?
Both have a free tier, so you can try either at no cost before committing.
What is DataStax best used for?
DataStax is most often used for real-time applications, content management, user profiles, mobile backends. Of those, real-time applications and content management are not what FaunaDB is typically brought in for.
What can DataStax do that FaunaDB cannot?
DataStax covers Cassandra Compatible, Vector Search, Serverless, Multi-cloud. FaunaDB covers Document-relational model, FQL v10, Distributed ACID transactions, HTTPS access.

Answered from the vendors’ own pages

DataStax: Is DataStax available as a managed service?

Yes, DataStax is available as Astra DB, a managed database service. Users can sign up for Astra DB directly to create accounts and access the platform.

Source
FaunaDB: Can I still sign up for Fauna as a service?

No. Fauna Inc. wound down the hosted service in 2025 and the company website is no longer serving. The only way to run Fauna now is to build and operate the open-sourced server yourself.

DataStax: How is DataStax priced?

DataStax (now part of IBM) does not publish pricing on its documentation homepage. Pricing information would need to be obtained through the Astra DB signup page or by contacting IBM directly.

Source
FaunaDB: What licence is the open-sourced code under?

Apache 2.0, with the copyright held by a FaunaDB Foundation. That is a permissive OSI licence with no competing-use clause, so you may run it, modify it and even offer it as a service.

DataStax: Is there an enterprise licensing option?

DataStax is now part of IBM. Enterprise customers should contact IBM directly for licensing agreements and enterprise-specific pricing.

Source
FaunaDB: Is the open source version the same software that ran the cloud?

It is the core database engine. The control plane, billing, dashboard and multi-tenant operational tooling that made it a service are not part of the release, so you are running the engine, not the product.

DataStax: Can I try DataStax without an account?

To use DataStax Astra DB, account creation is required. The documentation does not mention a free trial or demonstration environment that does not require signup.

Source
FaunaDB: What should I migrate to?

There is no drop-in target. Teams that valued the document model with relationships usually land on Postgres with JSONB, and teams that valued the serverless HTTP access pattern usually land on DynamoDB or a managed Postgres with an HTTP driver. Either way the query layer is rewritten.

FaunaDB: How hard is it to self-host?

It builds as a fat JAR and runs as a multi-node JVM cluster. There is an OPERATING.md, but no supported packaging, no operator, no upstream releases and no support contract, so budget for a distributed-systems engineer, not a container.

Share

Related pages

More on DataStax

More on FaunaDB

Keep looking

Other head to heads