Most important O Auth providers to integrate with?
It's always nice having a one click sign in on your product, whether it be Google, Twitter, GitHub, Stack Overflow, Facebook, etc.
One trade off you make is that people can forget which provider they used to sign up to your product.
So what do you use to allow sign ups?
Google and Apple login, Apple login because you have to if you are in the appstore and also it's a nice user experience.
Usually a bunch, but depends on the space. For B2B it's usually Google, Microsoft, Apple,... But none of the identity aggregators are that good, so it becomes a pain to pull in more than a few. Especially when you throw in user session management, multiple microservices, and external api clients.
I have a Slack app, so I use Slack for that. I'm working on a Twitter app, so I use Twitter for that. Simplifies the signup and configuration considerably.
One neat technique to solve the problem of having users that potentially forget what providers they sign in with is saving the last used auth provider to localstorage .Then show a label in the sign up form next to the last used provider to remind the user how they signed up or logged in last time. Found this in divjoy and thought in was smart.
Yeah that's pretty sweet. localstorage can be wiped though. I've also thought that as long as the email is the same, when someone tries to login with the "wrong" provider you can check in the backend and tell them.
YMMV, but I had Google, Facebook, Twitter and Slack as sign up options on my site.
Overwhelmingly by like 90+%, Google was the most-used option. I've since removed Slack (nobody used it) and added regular email signup (which gets quite a lot of sign ups).
I think in a future revision I could reduce it to just Google OAuth and Email signup, and see almost no difference in sign up rate.
Cheers for the data point. Will also just stick with Google for now
I personally love Firebase Auth because it allows to easily enable new providers without changing the code much.
I would say go for GitHub if your target is mainly devs, otherwise Facebook and Twitter if you're targeting consumer market.
And don't forget Apple Sign-in if you're building a mobile app. It's mandatory if you provide third party sign-in.
For reference, on How to X with Y I've integrated with Google so far, with Twitter and StackExchange disabled for now.
Think about it from the user perspective first.