Firebase Authentication vs Keycloak: Pricing and Ratings Compared (2026)
Entry prices and free plans as read on each vendor's pricing page, and user ratings as published on review sites, for Firebase Authentication and Keycloak side by side. This page compares data; it is not a hands-on review.
On the data: On the data below the two are close or not directly comparable, so we do not name a winner for this pair.
Short on time? Here's the quick answer
Based on published vendor pricing and features and on public review data, here's who should pick what:
Firebase Authentication
Backend authentication by Google
Best for you if:
- • You want easy to implement
Keycloak
Open-source identity and access management
Best for you if:
- • You want a fully free tool (Firebase Authentication requires payment)
| At a Glance | Firebase Authentication | |
|---|---|---|
Starts at | Free plan | Free 100% free |
Category | Identity & Access Developer Tools | Identity & Access Security |
Rating | 4.9/5 G2 4.9 5 reviews | n/a |
Free plan | Yes | Yes |
Watch out for | Phone verification costs $0.01-$0.06 each. | n/a |
Choose Firebase Authentication or Keycloak?
Choose Firebase Authentication if
- You want easy to implement
- You want multiple auth methods
Choose Keycloak if
- You want a fully free tool (Firebase Authentication requires payment)
- You want open source identity
- You want self-hostable
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
- Pro: Easy to implement
- Pro: Multiple auth methods
- Pro: Free generous tier
- Pro: Good security
Weaknesses
- Con: Vendor lock-in
- Con: Limited customization
- Con: 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
- Pro: Open source identity
- Pro: Self-hostable
- Pro: Feature rich
- Pro: No per-user cost
- Pro: Enterprise ready
Weaknesses
- Con: Complex to set up
- Con: Requires maintenance
- Con: Learning curve
- Con: Java-based
- Con: UI dated
Key features
Plans and prices: Firebase Authentication vs Keycloak
| Tool | Plans and prices | Source |
|---|---|---|
| Firebase Authentication |
| firebase.google.com/products/auth read Oct 5, 2026 |
| Keycloak |
| keycloak.org read Sep 28, 2026 |
Prices as read on each vendor's own pricing page on the date shown. Plans are listed per tool and are not matched against the other tool's plans: a plan name or price in one column says nothing about the same row in the other. Details on Firebase Authentication pricing and Keycloak pricing.
Key Takeaways
Firebase Authentication
- Choose if you want backend authentication by Google
Keycloak
- Choose if you want open-source identity and access management
What the data shows
On the data below the two are close or not directly comparable, so we do not name a winner for this pair.
- Only Firebase Authentication has a published user rating (4.9/5 from 5 reviews); Keycloak has none we can show.
- Both have a free plan.
Criteria: user rating (only above 20 reviews on both sides, gap of 0.2 or more), entry price (only on the same billing basis), free plan. How we rate
Frequently Asked Questions
How do Firebase Authentication and Keycloak compare in 2026?
On the data below the two are close or not directly comparable, so we do not name a winner for this pair. Only Firebase Authentication has a published user rating (4.9/5 from 5 reviews); Keycloak has none we can show. Both have a free plan.
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 has no public paid-plan price on file. Keycloak is free. Prices read on the vendors' pricing pages, latest check Oct 5, 2026.
What's the main difference between Firebase Authentication and Keycloak?
Firebase Authentication's main strength: easy to implement. Keycloak's main strength: open source identity.