[amake]

> I mean, if this uses the same calculation as Twitter, Instagram and other sites that limit characters

Almost certainly those sites use much more sophisticated counting schemes.

> Honestly, I don't know, I did not expect for this to go so deep

You're not the creator of the tool in question, so it's OK for you not to know about this stuff, but I would really expect more from someone who is setting out to create a "character counter" tool.