This API is clearly not well supported. Indeed, only Google Chrome and Opera support it. However, this doesn’t mean you should not consider using it. First, Chrome is the most used browser. If you look at CanIUse, it represents about 67% of all users. Plus, using this API doesn’t break default login flow on other browsers. Instead, this API just improves it when it is available.
This new API is a great test improvement for the user as it simplifies the login process. You can now automatically log the user in without they notice it. While this new API is not well supported (currently Chrome and Opera), you can already use it to progressively replace the old login form. This post does not cover all the methods of this API. For instance, we do not use the store method which may be required for a SPA application. If you want to go further, here’re some additional resources: