I'm just starting a new side project, and have looked at Keycloak and fusionauth. Fusionauth has a free offering (ie, self hosted), and takes a minute to install and run. I like it a lot and am going forward with it for testing.
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.
Depending on what set of features you need, it may make sense to also have a look at SuperTokens.io. Probably not as mature but we're open source and stronger with customization of the end user experience (frontend stuff), support and ease of implemenetation.
> stronger with customization of the end user experience
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/
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.