[Gene Eric]

You’re right, I lapsed. The BOM helps to designate byte order — duh...

Still yet, how does one know if the stream is ANSI or UTF-8 until things get weird? At least with UTF-16+, the ANSI stream dies after the first character.

[cynwoody]

Still yet, how does one know if the stream is ANSI or UTF-8 until things get weird?

The server informs the browser how the page is encoded via the Content-Type header, e.g.,

Cache-Control:private
Connection:close
Content-Type:text/html; charset=utf-8
Date:Tue, 19 Jan 2016 16:45:16 GMT
Server:nginx/1.2.4
Transfer-Encoding:chunked

There are other possible values for the charset, but UTF-8 is taking over, because it just works.

[dinodino]

It’s not hard—if the first bit is set, it’s a multibyte character.

[smokingfrog]

https://www.w3.org/International/O-HTTP-charset