Gluu Flex vs Ipsilon
A side-by-side comparison of two self-hosted identity & sso options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | Gluu Flex | Ipsilon |
|---|---|---|
| Deploy effort | Under-an-hour setup | Read-the-docs project |
| Category | Identity & SSO | Identity & SSO |
| License | Apache-2.0 | GPL-3.0 |
| Language | TypeScript | Python |
| Setup difficulty | Hard | Hard |
| Min. RAM | 4,096 MB | 512 MB |
| Deployment | docker, kubernetes, helm | bare-metal, source |
| GitHub stars | ★ 31 | ★ 80 |
| First released | 2009 | 2014 |
| Replaces | Okta, Ping Identity | Okta, PingFederate |
What are Gluu Flex and Ipsilon?
Gluu Flex
Gluu provides a self-hostable identity platform for single sign-on, multi-factor authentication, and access management built on open standards. It supports OAuth, OIDC, SAML, and FIDO2.
- Single sign-on
- OAuth, OIDC and SAML
- FIDO2 strong authentication
- Kubernetes deployment
Ipsilon
Ipsilon is an identity provider service that supports SAML and OpenID for federated single sign-on. It plugs into existing authentication backends like FreeIPA to centralize login for web applications.
- SAML identity provider
- OpenID support
- FreeIPA integration
- Pluggable backends
Gluu Flex vs Ipsilon: key differences
Gluu Flex is written in TypeScript, while Ipsilon is built with Python. Licensing differs — Apache-2.0 for Gluu Flex versus GPL-3.0 for Ipsilon. Ipsilon is the lighter option, starting around 512 MB of RAM against 4,096 MB for Gluu Flex. Gluu Flex is the more established project (first released 2009), while Ipsilon arrived in 2014. Ipsilon has the considerably larger community, at 80 GitHub stars versus 31. Gluu Flex lists first-class Docker deployment; Ipsilon does not.
Why pick each one
Choose Gluu Flex if…
- Released under the Apache-2.0 license
- First-class Docker support for quick deployment
- Kubernetes-ready with Helm charts available
- Written in TypeScript
Choose Ipsilon if…
- Good FreeIPA companion
- Federation focused
Watch out for
- Small community
- Limited recent activity
Frequently asked questions
Is Gluu Flex or Ipsilon better?
Neither is universally better. Ipsilon has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are Gluu Flex and Ipsilon free and open-source?
Yes. Gluu Flex is licensed under Apache-2.0 and Ipsilon under GPL-3.0. Both can be self-hosted at no software cost.
Can I run Gluu Flex and Ipsilon with Docker?
Gluu Flex: yes. Ipsilon: check the project docs for container support.
Which is lighter on resources, Gluu Flex or Ipsilon?
Ipsilon has the smaller minimum footprint at 512 MB of RAM, compared to about 4,096 MB for Gluu Flex. Real-world usage depends on library size, user count, and enabled features.