How to send push notifications?

Question

JavaScript

Good time of the day!
There are services like sendpulse.com that allow you to send push messages.

• I understand correctly, these are the same HTML5 Notifications?
  
• How do they manage to work when the site is closed?
  
• How to send messages yourself if the site is not open?
  

Answer 1

It's better to send via PushAll
But if you do it yourself, then dig towards the Push API. https://github.com/chrisdavidmills/push-api-demo
But you need to understand that you can only get it for free on chrome, ff and what is based on them. On Safari, you need to make a certificate through an Apple developer account; for mobile platforms, applications must be written.
Well, the most difficult thing is to maintain up-to-date tokens, update them, monitor the relevance of connected devices.
To put it more clearly, when the site is closed, it is sent through the browser services, then it calls your code in the Service Worker and it already displays a notification.
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