The Telegram web client (at https://web.telegram.org/) can send me notifications even when no telegram.org web page is loaded into any open tab in my Chromium web browser.
How is it possible for a website that was loaded in the past, but is not loaded at present, to cause my computer to display notifications?
I am running Chromium on Ubuntu 18.04, but I have observed this with a previous version of Ubuntu such as 16.04 and/or 14.04.
Some more background information:
The Settings pop-up for the Telegram web app has the following options:
Desktop notifications (on/off)
Background notifications (on/off)
Message preview (on/off)
Sound (on/off)
There is no documentation that explains the difference between Desktop and Background notifications. However, I now suspect that Background notifications are what happens when no Telegram tabs are open.
Also, in the Settings for Chromium itself, I can see that I have Allowed notifications for https://web.telegram.org:443.
So, my question is, how does Telegram (or any other web app) request (or configure, or set up) background notifications? Where is the documentation on how these notifications work in the web browser?
Is there any way (in the browser, not the app) to disable background notifications while still allowing foreground notifications?
I find it scary that notifications can still occur after I have closed the Telegram tab.
Best Answer
Many extensions and web apps use background pages that do their work where you can't see them. For example, if you use Google Mail Checker, a background page works to send new message alerts. Background apps work entirely in the background and run even after you close the Chrome browser. Background pages and apps use your computer's resources. You can check to see how much they're using, and you can turn them off at any time.