Does Firebase or Keycloak have a free plan?

Both do: Firebase has a free tier with limits, and Keycloak is free.

What is the difference between Firebase and Keycloak?

On the criteria we check, only Firebase has mobile app and only Keycloak has open source / self-hostable; both offer public api and sso (saml). The table above lists every criterion side by side.

All tools

Firebase vs Keycloak

A source-aware comparison of pricing, documented capabilities and workflow fit.

Short answer

This is really Firebase Authentication versus Keycloak. Firebase Auth is a hosted service inside Google's app platform: email, phone and social sign-in with native SDKs for iOS, Android, web and Flutter, and nothing to run yourself; enterprise protocols such as SAML and OpenID Connect providers arrive through the paid Identity Platform tier. Keycloak is a self-hosted identity server from the Red Hat-backed open-source project: SAML 2.0 and OpenID Connect out of the box, LDAP and Active Directory user federation, realms for multi-tenancy, fine-grained roles and identity brokering to other providers. It ships no mobile SDK; apps talk to it through standard OIDC flows. The choice is operational: zero-ops managed auth for app teams versus full control and data ownership for platform teams.

Firebase is the pick when

you are already on Firebase or Google Cloud and want auth wired to Firestore rules in an afternoon
the product is mobile-first and you want first-party iOS, Android and Flutter SDKs
nobody on the team wants to run, patch or back up an identity server

Keycloak is the pick when

you need SAML, LDAP or Active Directory federation without a per-user cloud bill
users, sessions and tokens must stay on your own infrastructure
you run several tenants or brands and want realm-level isolation

Ready to try?Visit Firebase Visit Keycloak

Written by hand from both vendors’ own documentation, checked 2026-09-15. Sources: Firebase Authentication docs, Keycloak documentation. Prices below come from the pricing we track. How we score tools.

What Firebase is

Firebase is Google's comprehensive platform for solving all mobile and web backend needs via a single SDK. It lets developers build 'real-time' apps without server management. Its Firestore DB scales infinitely on Google Cloud. It's a massive ecosystem that also manages analytics, crash reports, A/B tests, and push notifications from a single panel.

What Keycloak is

Keycloak is open-source identity and access management supporting OIDC and SAML, run on your own infrastructure. Running it yourself means user data and session policy stay inside your infrastructure, which is often the deciding factor in regulated environments. The price is that authentication becomes something your team operates, upgrades and keeps available.

	Firebase	Keycloak
Category	Developer Tools	Developer Tools
How to start	Free tiernot a monthly price	Freeverified
Public API	Yes	Yes
Mobile app	Yes	No
Open source / self-hostable	No	Yes
SSO (SAML)	Yes	Yes
Visit	Firebase ↗	Keycloak ↗

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What Firebase is built to do

Cloud Firestore: A flexible NoSQL document database that stays synced globally at scale.
Authentication: Install a secure login system for email, phone, or social accounts with one click.
Cloud Functions: Run your custom code as serverless functions triggered by events.
Push Messaging: Send unlimited push notifications to iOS, Android, and Web users for free.

What Keycloak is built to do

OIDC and SAML: Acts as an identity provider for both protocols and brokers external ones.
Realms and roles: Separates tenants into realms with their own users, clients and role mappings.
Self-hosted: Runs on your own infrastructure so credentials never leave it.

Choose Firebase if

Prototypes and small apps: the Spark plan needs no payment method and its quotas (50K Firestore reads a day, 10 GB Hosting storage) carry over into the paid plan
Teams that want analytics, Crashlytics, Cloud Messaging, A/B testing and Performance Monitoring at no cost regardless of plan
Apps with fewer than 50,000 monthly active users, where Authentication is free
Mobile teams needing device testing occasionally — 60 virtual and 30 physical device minutes a day are free before $1 and $5 per device-hour

Skip Firebase if

You want a bill you can predict: Blaze is metered per read, write, GB and invocation, and beyond Firebase's own table most services fall through to Google Cloud pricing
Your app is read-heavy — Firestore's free tier is a daily 50K reads, and a busy client that re-reads documents is the classic source of surprise Firebase bills
You serve large files or video: Hosting includes only 360 MB of transfer a day, then $0.15/GB, and Realtime Database downloads are $1/GB
You need a hard spend cap — the pricing plans are a free tier and pay-as-you-go, with budget alerts rather than a stop-at-limit switch

Choose Keycloak if

Teams that want a free, Apache-licensed identity server with OpenID Connect, OAuth 2.0 and SAML 2.0
Organisations that must keep identity data on their own infrastructure
Companies that want a CNCF project rather than a per-MAU SaaS bill

Skip Keycloak if

You have nobody to run and upgrade it: Keycloak is self-hosted and the operational cost is yours
You need vendor support without a Red Hat subscription
You want a managed service with a free tier and no servers — Auth0 or Clerk fit that better

Evidence and freshness

Where a claim on this page comes from a vendor page, it is linked here.

Firebase

Vendor pricing page verified · reviewed 2026-09-09

Firebase — Pricing ↗

Keycloak

Open source, free — vendor page verified · reviewed 2026-09-08

Firebase: pros & cons

Speed: Set up a functioning backend and auth system in as little as one day.
Google Synergy: Works perfectly with Google Analytics and Google Cloud Platform.
Generous Free Plan: Costs are zero for many small to medium-sized projects.
Real-Time Sync: The leader for apps needing instant data updates like chat apps.
Lock-In: Moving away from Firebase is very difficult due to its unique NoSQL structure.
Query Limits: Not as flexible as SQL for very complex relational data queries.
Cost Prediction: 'Pay-as-you-go' can strain budgets if traffic spikes unexpectedly.

Keycloak: pros & cons

Full identity server at no licence cost
Standards support including SAML and OIDC
Complete control over user data
Operating it is a real responsibility
Administration console is dense
Upgrades need care

Our verdict on Firebase

The strongest ecosystem for those who want to focus on features instead of server management.

Our verdict on Keycloak

The serious open-source answer to Auth0. Budget for the operations, because the licence saving is not free.