Softwr

Databases · head to head

Firestore vs Keycloak

Firestore logo

Firestore

Databases

Flexible, scalable NoSQL cloud database from Firebase

From
Free
Free plan
Yes
Visit FirestoreFull review
Keycloak logo

Keycloak

Developer Tools

Open-source identity and access management server.

From
Free
Free plan
Yes
Visit KeycloakFull review

The short version

  • Keycloak is an open-source IAM platform supporting OpenID Connect, OAuth 2.
  • Both are free.
  • Where Firestore falls short: the no-cost Spark plan caps Standard edition at 50,000 document reads, 20,000 writes and 20,000 deletes per day.
  • Where Keycloak falls short: requires self-hosted deployment and operational expertise to install, configure and maintain.
  • Prices and features on this page were last checked on 13 November 2026.

Where they differ

Only the attributes on which Firestore and Keycloak actually diverge.

Attributes where Firestore and Keycloak differ
AttributeFirestoreKeycloak
Pricing modelFreemiumOpen-source
PlatformsWeb, iOS, Android, FlutterSelf-hosted, Linux, Windows, API
CategoryDatabasesDeveloper Tools

Identical on both: starting price (Free), free tier (Yes).

Not yet recorded: founded for Keycloak.

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 Firestore

  • Document Model
  • Real-time Updates
  • Offline Support
  • ACID Transactions
  • Expressive Queries
  • Multi-region
  • Security Rules
  • Firebase Auth

Only in Keycloak

Nothing recorded that Firestore does not also cover.

What people use each for

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

Firestore

  • Storing structured application data with realtime listenersnot Keycloak
  • Backing mobile and web apps with a serverless document databasenot Keycloak
  • Building offline first apps that sync when connectivity returnsnot Keycloak

Keycloak

  • Organisations requiring self-hosted identity infrastructure for compliance or data residencynot Firestore
  • Companies with existing LDAP/Active Directory systems needing federated authenticationnot Firestore
  • Open-source projects and communities requiring free IAM without licensing costsnot Firestore
  • Enterprises building custom identity workflows requiring fine-grained authorisationnot Firestore
  • Teams with sufficient operational expertise to manage infrastructurenot Firestore

Where each one falls short

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

Firestore

  • The no-cost Spark plan caps Standard edition at 50,000 document reads, 20,000 writes and 20,000 deletes per day
  • The Spark plan caps storage at 1 GiB and network egress at 10 GiB per month
  • Charging is per document read, so a query returning many documents bills for every one of them
  • Going beyond the free thresholds requires the pay as you go Blaze plan billed at Google Cloud rates with no fixed monthly ceiling

Keycloak

  • Requires self-hosted deployment and operational expertise to install, configure and maintain
  • No managed cloud option provided by Red Hat; organisations must operate infrastructure themselves or use third-party distributions
  • Clustering and high-availability configurations require additional operational knowledge
  • Community support only; commercial support requires third-party vendors or distributions

Pricing, plan by plan

Firestore

Free
  • SparkFree
    • 1GB storage
    • 50K reads/day
    • 20K writes/day
  • BlazeFree
    • Pay as you go
    • Unlimited operations
    • Multi-region

Keycloak

Free
  • Open-sourceFree
    • Full platform functionality
    • Self-hosted deployment
    • Community support

Which should you pick?

Choose Firestore if

  • You need document model.
  • You want to start without paying.
  • You work on Web, iOS, Android, Flutter.
  • You also want real-time updates.
Firestore review

Choose Keycloak if

  • You want to start without paying.
  • You work on Self-hosted, Linux, Windows, API.
Keycloak review

Questions people ask

Is Firestore or Keycloak better?
Neither clearly leads. Firestore starts at Free and Keycloak at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Firestore or Keycloak?
Firestore starts at Free and Keycloak at Free.
Does Firestore or Keycloak run on more platforms?
Firestore runs on Web, iOS, Android, Flutter. Keycloak runs on Self-hosted, Linux, Windows, API.
Can I use Firestore for free?
Both have a free tier, so you can try either at no cost before committing.
What is Firestore best used for?
Firestore is most often used for storing structured application data with realtime listeners, backing mobile and web apps with a serverless document database, building offline first apps that sync when connectivity returns. Of those, storing structured application data with realtime listeners and backing mobile and web apps with a serverless document database are not what Keycloak is typically brought in for.
What can Firestore do that Keycloak cannot?
Firestore covers Document Model, Real-time Updates, Offline Support, ACID Transactions.

Answered from the vendors’ own pages

Firestore: What are the free limits on Cloud Firestore?

The Spark Plan includes 1 GiB of stored data, 50,000 reads per day, 20,000 writes per day, and 20,000 deletes per day at no cost.

Source
Keycloak: What protocols does Keycloak support?

Keycloak supports OpenID Connect, OAuth 2.0 and SAML 2.0 protocols for authentication and authorisation.

Source
Firestore: What happens when I exceed the Spark Plan free tier?

Exceeding the free tier requires upgrading to the Blaze Plan, which bills based on actual usage through Google Cloud pricing. Charges apply for reads, writes, deletes, and data storage.

Source
Keycloak: Can Keycloak integrate with existing user directories?

Yes. Keycloak supports user federation with LDAP and Active Directory systems, allowing organisations to leverage existing user directories.

Source
Firestore: Can I use Firestore without a credit card?

Yes, you can use the Spark Plan indefinitely without a credit card. To use the Blaze Plan (pay-as-you-go), a credit card is required.

Source
Keycloak: Is Keycloak free?

Yes. Keycloak is fully open-source and free to deploy and use. No licensing fees are required.

Source
Firestore: Is there a trial period for Cloud Firestore?

No trial period is specified. The Spark Plan free tier serves as the trial, with no time limit.

Source
Share

Related pages

More on Firestore

More on Keycloak

Keep looking

Other head to heads