Which is the first multi-byte UTF codepoint?

Question

I just wanted to know which unicode blocks can be safely used when being limited to single-byte codepoints only.

So, which is the last single-byte codepoint, and which is the first multi-byte codepoint?

Answer 1

In UTF-8, the last single-byte code point is U+007F, and first 2-byte code point is U+0080.

See https://en.wikipedia.org/wiki/UTF-8#Encoding