Android push notification without firebase

Solution 1:

The way is to create custom Service https://developer.android.com/reference/android/app/Service.html , which is holding connection via socket or polling some remote server with intervals.

But, I suggest that Firebase service is more advanced and optimized in battery consumption and, particularly, in utilizing the sleep mode. It's not trivial to make a service which will have fast response and CPU consumption. I think that a custom service development will lead to native (C++) coding of networking routines libs.

Also, take into account that Firebase provides own Authentication service with ability to seamless convert your anonymous user to registered. There is a lot of pros of Firebase services. And cons are: your users have to install Google Play Services, if your app will grow - you will pay to Firebase.

Look here Android push notification without Google service

Solution 2:

It's possible using VAPID authentication.

Google for VAPID and you will find a very tortuous road that could lead to the answer you are looking for.