Surprisingly your the only one who has mentioned Keycloak so far?! I switched several projects from Auth0 to it some time ago and didn't look back... particularly when they started tightening things since said projects were not even profitable.
Keycloak is a pain to set up, and its configuration tends to get quite messy — besides, we try to cover integrations into the entire stack (frontend to the database).
I keep repeating this comparison throughout this thread, but Stack is to Keycloak/Ory/etc. what Clerk is to Auth0.
Though, I regularly recommend Keycloak in sales calls when I talk to larger companies willing to invest time and effort into a custom IdP. We are not really looking to replace those use cases.
Keycloak, while complex, doesn't feel overly complex. It exposes the complexity of the auth space to you.
On the other hand, Auth0 attempts to close of the complexity of the space by creating an opaque/proprietary layer. And then the primary pain point with Auth0 is that it's feature are behind another pricing tier.
If less complexity is what Stack Auth does differently than Keycloak. Does it do so by having a less transparent view of the auth process? Or does it do it by surfacing this complexity in a more digestible format?
