Keycloak vs Auth0: an honest comparison
In short
- Auth0: fastest to start, fully managed, priced by active users.
- Keycloak: open source, no per-user fees, full control, but you run it.
- The bigger your user base and the more you need to customise, the stronger the case for Keycloak.
Side by side
| Keycloak | Auth0 | |
|---|---|---|
| Licence | Open source (Apache 2.0) | Commercial SaaS |
| Pricing | Free; you pay for hosting and expertise | Subscription based on monthly active users |
| Hosting | Anywhere, including Australian regions or on-prem | Auth0's cloud |
| Customisation | Unlimited: themes, flows, Java extensions | Within the platform: Actions, Universal Login |
| Operations | Your team or provider runs it | Fully managed |
| Time to first login | Days | Hours |
When Auth0 is the better choice
- Small user base, where per-user pricing stays low
- No one on the team to run and patch identity infrastructure
- You need something live this week
When Keycloak wins
- Scale: costs don't climb with every new user
- Data sovereignty: keep identity data onshore, in your own environment
- Custom requirements: unusual login flows, legacy user stores, deep integration
- No lock-in: open standards and open source, so you can change hosting any time
Moving from Auth0 to Keycloak
Most migrations come down to three questions: can you export password hashes, how do Auth0 Actions map to Keycloak flows and extensions, and how will each app cut over? Our migration planning service answers all three before you commit.
Keycloak vs Auth0 FAQ
Is Keycloak really free?
The software is free and open source. You still pay for hosting, maintenance and the expertise to run it well.
Can users keep their passwords when moving from Auth0?
Often, yes. Exported password hashes can usually be imported, or users can be migrated the first time they log in.
Weighing up Keycloak vs Auth0? Get an independent opinion. We don't resell either.