Which engine does the stock Samsung Browser use? Is it based on WebKit, Gecko, or something else?
3 Answers
Android default browser uses WebKit. Check out the second paragraph of Wikipedia WebKit description.
After reviewing some user-agent strings, all native Samsung browsers I saw use WebKit.
There are particular idiosyncrasies when working with this family browser amongst devices, and a lot of weird behavior. According to What browser does the Samsung Galaxy use? on Stack Overflow, there is some "value-added" by Samsung to the AOSP browser.
It is based on Chromium, it uses Blink (WebKit fork). https://en.wikipedia.org/wiki/Samsung_Internet