Are propietary browsers versions of Android Browser?

Question

Checking http://caniuse.com/#search=transition You can see that android browser has a significative amount of share world wide, but in this site there is no notice of samsung browser or LG browser.

I've checked an old Samsung G. Trend 2 and it featres Samsung Browser 2.1 and my LG comes with a browser with 5.70.** version.

I have 3 questions:

1. Are these browsers implementations of Android Browser?
2. How to check the share rates from those browsers?
3. If they are the same, how can I know which features do those browsers support?

Answer 1

Are these browsers implementations of Android Browser?

"Android Browser" means "is a wrapper of (Chromium) webview", Android's built-in browser. You can be fairly certain that most stock browsers do use it. But Android does not prevent browsers from coming with their own engine. Firefox is the most prominent example, others exist.

For Samsung Browser, it is documented that it uses chromium. For the LG browser, I couldn't find a documentation, but the app internally calls the UI element that displays websites "webview_wrapper", which is a strong hint at least.

How to check the share rates from those browsers?

You can tell the browsers apart by the User-Agent header they send with requests, but the global statistics websites I know of don't differentiate between the different webview-wrappers. (Should you go searching on your own, mind that "Samsung Internet" might be Samsung's own Webkit based browser, not the default one.)

If you really need to know, then the best solution here would probably be to evaluate your own server logs.

If they are the same, how can I know which features do those browsers support?

It is best practise to perform online feature detection rather than to add version checks to your website. If you do that, then you don't have to care about this question. See e.g. https://modernizr.com/.