Nintendo Switch does not have a normal Internet Browser for user usage. However, there is multiple browser applets. It is the NetFront NX browser, which is based on Webkit.
When linking the Nintendo Account with Facebook, the Facebook Auth website will open, offering a search box that can be used to browse the Internet ("LoginApplet"). Alternatively, it can be accessed with custom DNS settings which simulate a Wi-Fi login page ("WifiWebAuthApplet" for captive-portal).
Known User Agent Strings
|System Software||Release Date||UA String|
|Unknown||Unknown||Mozilla/5.0 (Nintendo Switch; WebApplet) AppleWebKit/601.6 (KHTML, like Gecko) NF/220.127.116.11.19 NintendoBrowser/18.104.22.16886|