Stack Auth vs Keycloak: Which is Better in 2026?
Choosing between Stack Auth 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. LastPass is our overall Identity & Access pick. LastPass is our free Identity & Access pick. Pick Stack Auth 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:
Stack Auth
Open-source authentication and user management for developers, designed for rapid integration and flexibility.
Best for you if:
- • You want open-source, offering flexibility and control
- • You want quick and easy setup, replacing existing auth solutions in hours
Keycloak
Open-source identity and access management
Best for you if:
- • You want a fully free tool (Stack Auth requires payment)
- • You want open source identity
- • You want self-hostable
| At a Glance | Stack Auth | |
|---|---|---|
Starts at | FreeFree tier available | FreeFree tier available |
Best For | Identity & Access | Identity & Access |
Rating | - | - |
Free plan | Yes | Yes |
Choose Stack Auth or Keycloak?
Choose Stack Auth if
Open-source authentication and user management for developers, designed for rapid integration and flexibility.
- You want open-source, offering flexibility and control
- You want quick and easy setup, replacing existing auth solutions in hours
Choose Keycloak if
Open-source identity and access management
- You want a fully free tool (Stack Auth requires payment)
- You want open source identity
- You want self-hostable
| Feature | Stack Auth | Keycloak |
|---|---|---|
| Pricing Model | Freemium | Free |
| User Rating | No ratings yet | No ratings yet |
| Categories | Identity & AccessDeveloper Tools | Identity & AccessSecurity |
In-Depth Analysis
Stack Auth
Open-source authentication and user management for developers, designed for rapid integration and flexibility.
Stack Auth's pricing is fair for its target audience.
Strengths
- +Open-source, offering flexibility and control
- +Quick and easy setup, replacing existing auth solutions in hours
- +Comprehensive feature set for B2B and complex user management
- +Manages JWTs and access tokens automatically
- +Developer-friendly with client/server APIs and UI components
Weaknesses
- -Specific details on self-hosting are not immediately clear from the provided content
- -Limited SAML SSO connections in lower-tier paid plans
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: Stack Auth vs Keycloak
| Plan | Stack Auth | Keycloak |
|---|---|---|
| Tier 1 | Free Free | Free Open Source |
| Tier 2 | $49 / mo Team | N/A |
| Tier 3 | $299 / mo Growth | N/A |
Pricing verified from each vendor's public pricing page. Compare in detail on Stack Auth pricing and Keycloak pricing.
Who Should Use What?
On a budget?
Keycloak is free. Stack Auth is freemium.
Go with: Keycloak
Want the highest-rated option?
Neither has ratings yet.
Too early to call on ratings, compare on features and pricing.
Value user reviews?
Neither has ratings yet.
Too early to call, neither has ratings yet.
3 Questions to Help You Decide
What's your budget?
Stack Auth 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?
Neither has ratings yet.
Key Takeaways
Keycloak
- Completely free
- Our pick for this comparison
Stack Auth
- Choose if you want open-source authentication and user management for developers, designed for rapid integration and flexibility
The Bottom Line
Keycloak wins this matchup. LastPass is our overall Identity & Access pick. LastPass is our free Identity & Access pick.
Frequently Asked Questions
Is Stack Auth or Keycloak better?
Keycloak is rated in our evaluation. Stack Auth is freemium and Keycloak is free.
What are Stack Auth and Keycloak used for?
Stack Auth: Open-source authentication and user management for developers, designed for rapid integration and flexibility.. Keycloak: Open-source identity and access management.
What does Stack Auth cost vs Keycloak?
Stack Auth is freemium (free tier + paid plans). Keycloak is completely free. Visit their websites for detailed pricing.