Which is quicker COALESCE OR ISNULL?

Question

I understand the difference between these functions but my question is when checking for a single null value would ISNULL be any quicker than using COALESCE?

e.g

Answer 1

Please check the link to prefer ISNULL over COALESCE when given the choice is that ISNULL tends to produce query plans that are more efficient than COALESCE.

1. ISNULL Vs COALESCE

2. ISNULL vs COALESCE speed test

3. Please check the Performance: ISNULL vs. COALESCE