Keycloak vs Auth0: the comparison you need before deciding
Auth0 is an excellent product. It's also expensive, proprietary, and increasingly tied to Okta. This page helps you evaluate both options without bias.
Quick comparison
| Auth0 | Keycloak | |
|---|---|---|
| Cost per user | Per MAU — scales fast | Fixed infrastructure |
| Full control | Limited (SaaS) | Total (open source) |
| Data sovereignty | Data on Okta servers | Wherever you decide |
| Vendor lock-in | High (Actions, marketplace) | Low (OIDC/SAML standards) |
| Time to production | Very fast (hours) | Requires configuration |
| Maintenance | Managed by Auth0 | Your team or a partner |
The real cost at scale
Auth0 charges per monthly active user (MAU). At small scale it's manageable. The problem appears when you grow.
| Active users | Auth0 | Keycloak |
|---|---|---|
| 30,000 MAU | $2,100/month | Infrastructure cost |
| 200,000 MAU | Negotiated pricing | Infrastructure cost |
Auth0 pricing varies by plan and may change. Verify on their website before comparing.
When Auth0 makes sense
- Early-stage startup with no infrastructure team
- MVP or proof of concept where speed is everything
- B2C SaaS product with a small, stable user base
- Team without technical capacity to operate infrastructure
When Keycloak wins
- Regulated sector: banking, healthcare, insurance, government
- Data sovereignty or EU residency requirements
- Complex architectures with identity federation or legacy systems
- Multi-tenant strategy with per-customer isolation
Why Keycloak + IDPTrust
Keycloak specialists
We're not IAM generalists. Keycloak is the only thing we do, and we know it in depth.
No surprises
We evaluate your case before recommending. If Auth0 is better for you, we'll tell you.
Full-cycle support
From architecture decisions to production deployment, documentation, and post-launch support.
Frequently asked questions
- Is Keycloak completely free?
- Keycloak is open source and free as software. The real cost is the infrastructure where you deploy it (servers, database, monitoring) and the team that operates it. Depending on your user volume, this cost can be significantly lower than Auth0's per-MAU pricing model.
- Can you migrate from Auth0 to Keycloak?
- Yes. Migration is technically feasible because both platforms use open standards (OIDC, OAuth 2.0, SAML). The effort depends on how much business logic you have in Auth0's Actions or proprietary flows. At IDPTrust we've executed several migrations of this type — the typical process covers analysis, user migration, flow reimplementation, and parallel validation.
- How much does Auth0 cost?
- Auth0 charges per monthly active user (MAU). As a reference, 30,000 MAU costs approximately $2,100 per month. Prices vary by plan and may change; check Auth0's website for current pricing.
- Do I need an in-house technical team to use Keycloak?
- Not necessarily. You can operate Keycloak with a specialized partner who manages the infrastructure and configuration for you. IDPTrust offers monthly retainer formats for organizations that prefer to outsource the operation of their Keycloak instance.
- Is Keycloak GDPR compliant?
- Yes, as long as you deploy it on infrastructure within the EU (or a region that meets data transfer requirements). Being self-hosted, you control where your users' identity data lives, which makes regulatory compliance much easier compared to third-party SaaS solutions.
Still evaluating?
Tell us about your situation. In 30 minutes we'll tell you which option makes more sense for your organization.
Talk to an expert