When do you show users a second character count?

My first instinct was to show one simple count. Then I ran into a problem: writers usually care about visible characters, while browser form limits can use UTF-16 code units. A draft can look fine in one counter and still fail a form field.

I’m considering two approaches:

1. Show only a simple count until someone selects a target like “web form”.

2. Show both counts from the start, with a short explanation.

I lean toward the first option because most people should not need Unicode terminology while writing.

For makers who have shipped character-limited inputs: when has an extra count prevented confusion, and when has it just added noise?