Choose the target quote (single or double), paste your code, then click Normalize. Only real string literals are re-quoted; comments and regex are untouched.
Yes. It walks the source character by character, tracking strings, comments and regex literals, so quotes inside comments or regex are never changed.
An escaped source quote (like \' in a single-quoted string) is unescaped, and any target quote inside the string is escaped, keeping the value identical.
No. Backtick template literals are left completely untouched, including any strings inside their ${...} expressions.