Firebase Authentication vs Keycloak: Which is Better in 2026?
Choosing between Firebase Authentication and Keycloak comes down to understanding what each tool does best. This comparison breaks down the key differences so you can make an informed decision based on your specific needs, not marketing claims.
Bottom line: Keycloak wins this matchup. Our overall Identity & Access pick is 1Password. Our free Identity & Access pick is Swiftlane. Pick Firebase Authentication if you need a free tier to start with.
Short on time? Here's the quick answer
We've tested both tools. Here's who should pick what:
Firebase Authentication
Backend authentication by Google
Best for you if:
- • You want easy to implement
- • You want multiple auth methods
Keycloak
Open-source identity and access management
Best for you if:
- • You want a fully free tool (Firebase Authentication requires payment)
- • You want open source identity
- • You want self-hostable
| At a Glance | Firebase Authentication | |
|---|---|---|
Starts at | FreeFree tier available | FreeFree tier available |
Best For | Identity & Access | Identity & Access |
Rating | 4.7/5 | - |
Free plan | Yes | Yes |
Choose Firebase Authentication or Keycloak?
Choose Firebase Authentication if
Backend authentication by Google
- You want easy to implement
- You want multiple auth methods
Choose Keycloak if
Open-source identity and access management
- You want a fully free tool (Firebase Authentication requires payment)
- You want open source identity
- You want self-hostable
| Feature | Firebase Authentication | Keycloak |
|---|---|---|
| Pricing Model | Freemium | Free |
| User Rating | ★4.7/5 771 reviews | No ratings yet |
| Categories | Identity & AccessDeveloper Tools | Identity & AccessSecurity |
In-Depth Analysis
Firebase Authentication
Backend authentication by Google
Firebase Authentication's Spark plan is incredibly generous, offering 50,000 MAU for free, which is far more than many competitors.
Watch out
Phone verification costs $0.01-$0.06 each.
Strengths
- +Easy to implement
- +Multiple auth methods
- +Free generous tier
- +Good security
Weaknesses
- -Vendor lock-in
- -Limited customization
- -Part of Google ecosystem
Key features
Keycloak
Open-source identity and access management
Keycloak's pricing is exceptionally generous, being entirely free as an open-source solution.
Strengths
- +Open source identity
- +Self-hostable
- +Feature rich
- +No per-user cost
- +Enterprise ready
Weaknesses
- -Complex to set up
- -Requires maintenance
- -Learning curve
- -Java-based
- -UI dated
Key features
Pricing: Firebase Authentication vs Keycloak
| Plan | Firebase Authentication | Keycloak |
|---|---|---|
| Tier 1 | Free Spark (Free) | Free Open Source |
| Tier 2 | Blaze (Pay as you go) | N/A |
Pricing verified from each vendor's public pricing page. Compare in detail on Firebase Authentication pricing and Keycloak pricing.
Who Should Use What?
On a budget?
Keycloak is free. Firebase Authentication is freemium.
Go with: Keycloak
Want the highest-rated option?
Firebase Authentication is rated 4.7/5. Keycloak has no ratings yet.
Go with: Firebase Authentication
Value user reviews?
Firebase Authentication: 771 reviews (4.7/5). Keycloak: no ratings yet.
Go with: Firebase Authentication
3 Questions to Help You Decide
What's your budget?
Firebase Authentication is freemium. Keycloak is free. Go with Keycloak if free matters most.
What's your use case?
Both are identity & access tools. Compare their specific features to decide.
How important are ratings?
Firebase Authentication is rated 4.7/5; Keycloak has no ratings yet.
Key Takeaways
Keycloak
- Completely free
- Our pick for this comparison
Firebase Authentication
- Choose if you want backend authentication by Google
The Bottom Line
Keycloak wins this matchup. Our overall Identity & Access pick is 1Password. Our free Identity & Access pick is Swiftlane.
Frequently Asked Questions
Is Firebase Authentication or Keycloak better?
Keycloak is rated in our evaluation. Firebase Authentication is freemium and Keycloak is free.
What are Firebase Authentication and Keycloak used for?
Firebase Authentication: Backend authentication by Google. Keycloak: Open-source identity and access management.
What does Firebase Authentication cost vs Keycloak?
Firebase Authentication is freemium (free tier + paid plans). Keycloak is completely free. Visit their websites for detailed pricing.