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Databases · head to head

FaunaDB vs Firebolt

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
Firebolt logo

Firebolt

Databases

Sub-second analytics at cloud data warehouse scale

From
$1.84/hour
Rated
-
Full reviewWebsite

The short version

  • Only FaunaDB has a free tier, so it costs nothing to try first.
  • Each has a real cost: 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.; Firebolt compute billed per second on Arm-based processors; small instances still incur measurable costs during idle periods despite auto-stop
  • They diverge on capability: FaunaDB covers Document-relational model, Firebolt covers Sub-second Queries.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which FaunaDB and Firebolt actually diverge.

Attributes where FaunaDB and Firebolt differ
AttributeFaunaDBFirebolt
Starting priceFree$1.84/hour
Pricing modelfreemiumusage-based
Free tierYesNo
PlatformsWebCloud (AWS, GCP, Azure preview), Docker, Kubernetes
Founded20122019

Identical on both: 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 FaunaDB

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

Only in Firebolt

  • Sub-second Queries
  • Sparse Indexes
  • Data Pruning
  • Decoupled Storage/Compute
  • SQL Support
  • Semi-structured Data
  • Workload Isolation
  • Airflow

What people use each for

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

FaunaDB

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

Firebolt

  • Data analytics teams running gigabyte-to-petabyte datasets with sub-second query requirementsnot FaunaDB
  • Real-time business intelligence platforms requiring ACID transactions and snapshot isolationnot FaunaDB
  • Applications needing vector search on analytical data for similarity queriesnot FaunaDB

Where each one falls short

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

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.

Firebolt

  • Compute billed per second on Arm-based processors; small instances still incur measurable costs during idle periods despite auto-stop
  • Storage pass-through charged at $0.0264/GB monthly on compressed data; uncompressed storage could exceed this
  • Azure deployment currently in Preview status; production recommendations unclear
  • Vector indexes limited to float arrays; other data types require alternative indexing strategies
  • Free tier credits ($200) limited; no perpetual free tier for production use

Pricing, plan by plan

FaunaDB

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

Firebolt

$1.84/hour

No published plan breakdown. See the Firebolt review.

Which should you pick?

Choose FaunaDB if

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

Choose Firebolt if

  • You need sub-second queries.
  • You work on Cloud (AWS, GCP, Azure preview), Docker, Kubernetes.
  • You also want sparse indexes.
Firebolt review

Questions people ask

Is FaunaDB or Firebolt better?
Neither clearly leads. FaunaDB starts at Free and Firebolt at $1.84/hour, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, FaunaDB or Firebolt?
FaunaDB has a free tier; the other does not. Paid plans start at Free for FaunaDB and $1.84/hour for Firebolt.
Does FaunaDB or Firebolt run on more platforms?
FaunaDB runs on Web. Firebolt runs on Cloud (AWS, GCP, Azure preview), Docker, Kubernetes.
Can I use FaunaDB for free?
Yes. FaunaDB has a free tier, so you can try it without paying. Firebolt starts at $1.84/hour.
What is FaunaDB best used for?
FaunaDB is most often used for keeping an existing fauna-backed application alive on self-hosted infrastructure while a migration is planned and funded, extracting historical data from a fauna dataset that can no longer be reached through the hosted api, studying a production implementation of deterministic distributed transactions, since the full server source is now readable under apache 2.0, forking the engine deliberately, where an organisation has jvm and distributed-systems staff and wants a document-relational store it fully controls. Of those, keeping an existing fauna-backed application alive on self-hosted infrastructure while a migration is planned and funded and extracting historical data from a fauna dataset that can no longer be reached through the hosted api are not what Firebolt is typically brought in for.
What can FaunaDB do that Firebolt cannot?
FaunaDB covers Document-relational model, FQL v10, Distributed ACID transactions, HTTPS access. Firebolt covers Sub-second Queries, Sparse Indexes, Data Pruning, Decoupled Storage/Compute.

Answered from the vendors’ own pages

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.

Firebolt: How does Firebolt's compute billing model work?

Firebolt uses per-second billing with scale-to-zero capability. The smallest S tier costs $1.84 per hour with 8 vCPU and 64GB memory, while the largest 4XL tier costs $58.88 per hour with 256 vCPU. Users only pay when compute is running.

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.

Firebolt: What is the cost for data storage on Firebolt?

Storage costs $0.0264 per GB per month on object storage, billed as pass-through cost at cloud provider rates.

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.

Firebolt: What free credits or trial does Firebolt offer new users?

New users receive $200 free credits to get started with the platform.

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.

Firebolt: Does Firebolt publish pricing for commitment-based discounts?

The pricing FAQ lists a question about commitment-based discounts but does not provide published answers on the pricing page. This requires direct inquiry with sales.

Source
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.

Firebolt: What deployment options does Firebolt offer besides managed service?

Firebolt offers self-hosted open source deployment (unlimited) and Bring Your Own Cloud (BYOC) options in addition to managed service.

Source
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