Having the auth system be your primary revenue stream means you pay very close attention to it, whether that be marketing or engineering. If it is just a freebie/side offereing you add to make your core better, well, it might lack resources or focus.
Disclosure, I work for FusionAuth.
However I don't see many web sites with a "sign in with FusionAuth" button, and I don't see any way to get such a button for my site.
Not without paying anyway - which is really my whole point. Free will always win.
You won't see a login with fusionauth button, you'll just see a login button on my website, which might give you Google, github,LinkedIn logins etc depending on what I choose.
I might say "a different approach" :) I appreciate SuperToken's SPA first stance, but FusionAuth is pretty darn customizable too: https://fusionauth.io/docs/v1/tech/themes/
Stay tuned for some major updates in the coming weeks! ;)
As a sibling comment mentioned, FusionAuth has a free offering if you self host. https://fusionauth.io/download/
My main complaint is that there is no ‘onLogin’ serverless functions hook, and how keeping additional user context through custom claims is not that straightforward.
And of course I’m pretty apprehensive about Google having the data, so best of luck to you all building OSS solutions.
Whereas Okta, Auth0, etc. cannot, since that is their product. So they have to charge.
Given network effects, a free auth system will always beat a paid one, except where the user is compelled to use it. (e.g. you want to use my SaaS product? You'll have to create an identity in my private auth system).
So I don't think these products (and I'll include KeyCloak which is fricking awesome) really compete as such with the FAANG offerings.