head to head · open source
Keycloak vs oauth2-client
Keycloak has 37,738 GitHub stars, 9,148 forks, 3,292 open issues and last shipped yesterday. oauth2-client has 3,819 stars, 770 forks, 64 open issues and last shipped 2 days ago. Keycloak leads on adoption by 888% (37,738 vs 3,819 stars). Keycloak is written in Java under Apache-2.0; oauth2-client is written in PHP under MIT. Keycloak has attracted 24% as many forks as stars, oauth2-client 20%. Keycloak was the more recently maintained of the two, and both are self-hostable with no licence fee.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Keycloak | oauth2-client | |
|---|---|---|
| GitHub stars | ★ 38K | ★ 3.8K |
| License | Apache-2.0 | MIT |
| Written in | Java | PHP |
| Last push | 2026-11-07 | 2026-11-06 |
| Forks | ⑂ 9.1K | ⑂ 770 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Keycloak if
- You weight community size — 38K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Java
- You value the larger contributor base for long-term maintenance
pick oauth2-client if
- You want the oauth2-client feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches PHP
- You evaluated both and oauth2-client fits your workflow better
About Keycloak
Open Source Identity and Access Management Add authentication to applications and secure services with minimum effort. No need to deal with storing users or authenticating users. Keycloak provides user federation, strong authentication, user management, fine grained authorization, and more. Help and Documentation Documentation User Mailing List Mailing list for help and general questions about Keycloak Join keycloak for general questions, or keycloak dev on Slack for design and development discussions, by creating an account at Reporting Security Vulnerabilities If you have found a security vulnerability, please…
read the full Keycloak overview →
About oauth2-client
OAuth 2.0 Client This package provides a base for integrating with OAuth 2.0 service providers. The OAuth 2.0 login flow, seen commonly around the web in the form of "Connect with Facebook/Google/etc." buttons, is a common integration added to web applications, but it can be tricky and tedious to do right. To help, we've created the league/oauth2 client package, which provides a base for integrating with various OAuth 2.0 providers, without overburdening your application with the concerns of RFC 6749. This OAuth 2.0 client library will work with any OAuth 2.0 provider that conforms to the OAuth 2.0 Authorization…
read the full oauth2-client overview →
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Frequently asked questions
Is Keycloak or oauth2-client more popular?
Keycloak has 37,738 GitHub stars and oauth2-client has 3,819. Keycloak has the larger community by that measure.
Are Keycloak and oauth2-client free?
Both are open source. Keycloak is licensed under Apache-2.0 and oauth2-client under MIT. Neither carries a licence fee.
What is the difference between Keycloak and oauth2-client?
Keycloak is written in Java and oauth2-client in PHP. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Keycloak or oauth2-client?
Choose Keycloak if you want the larger community (37,738 stars) or its Apache-2.0 licence terms. Choose oauth2-client if its feature set, stack or MIT licence fits better. Both are self-hostable.